NetBSD was originally derived from the 4.3BSD-Reno release of the Berkeley Software Distribution from theComputer Systems Research Group of theUniversity of California, Berkeley, via its History of theNet/2 source code release and the386BSD project.[5] The NetBSD project began as a result of frustration within the 386BSD developer community with the pace and direction of the operating system's development.[11] The four founders of the NetBSD project, Chris Demetriou,Theo de Raadt, Adam Glass, and Charles Hannum, felt that a more open development model would benefit the project: one centered on portable, clean, correct code. They aimed to produce a unified, multi-platform, production-quality, BSD-based operating system. The name "NetBSD" was chosen based on the importance andgrowth of networks such as theInternet at that time, and the distributed, collaborative nature of its development.[12]
The NetBSD source code repository was established on 21 March 1993 and the first official release, NetBSD 0.8, was made on 19 April 1993.[13] This was derived from 386BSD 0.1 plus the version 0.2.2 unofficialpatchkit, with several programs from the Net/2 release missing from 386BSD re-integrated, and various other improvements.[13][14] The first multi-platform release, NetBSD 1.0, was made in October 1994, and being updated with 4.4BSD-Lite sources, it was free of all legally encumbered 4.3BSD Net/2 code.[15] Also in 1994, for disputed reasons, one of the founders, Theo de Raadt, was removed from the project. He later founded a new project,OpenBSD, from a forked version of NetBSD 1.0 near the end of 1995.[16]In 1998, NetBSD 1.3 introduced thepkgsrc packages collection.[17]
Until 2004, NetBSD 1.x releases were made at roughly annual intervals, with minor "patch" releases in between. From release 2.0 onwards, NetBSD usessemantic versioning, and each major NetBSD release corresponds to an incremented major version number, i.e. the major releases following 2.0 are 3.0, 4.0 and so on. The previous minor releases are now divided into two categories:x.y "stable" maintenance releases andx.y.z releases containing only security and critical fixes.[18]
NetBSD used to ship withtwm as a preconfigured graphical interface (window manager); in 2020 (version 9.1) this was changed to the more modern and versatileCTWM.[19]
As the project's motto ("Of course it runs NetBSD" ) suggests, NetBSD has been ported to a numerous32- and64-bitarchitectures. These range fromVAXminicomputers toPocket PCPDAs. NetBSD has also been ported to severalvideo game consoles such as theSega Dreamcast[20] and theNintendo Wii.[21] As of 2019, NetBSD supports 59 hardware platforms (across 16 differentinstruction sets). The kernel anduserland for these platforms are all built from a central unified source-code tree managed byCVS. Unlike other kernels such asμClinux, the NetBSD kernel requires the presence of anMMU in any given target architecture.
NetBSD's portability is aided by the use ofhardware abstraction layer interfaces for low-level hardware access such asbus input/output orDMA. Using this portability layer,device drivers can be split into "machine-independent" (MI) and "machine-dependent" (MD) components. This makes a single driver easily usable on several platforms by hiding hardware access details, and reduces the work to port it to a new system.[22]
This permits a particular device driver for aPCI card to work without modifications, whether it is in a PCI slot on anIA-32,Alpha,PowerPC,SPARC, or other architecture with a PCI bus. Moreover, a single driver for a specific device can operate via several different buses, such asISA, PCI, orPC Card.
In 2005, as a demonstration of NetBSD's portability and suitability for embedded applications, Technologic Systems, a vendor of embedded systems hardware, designed and demonstrated a NetBSD-powered kitchentoaster.[23]
Commercial ports to embedded platforms were available from and supported by Wasabi Systems, including platforms such as theAMD Geode LX800,FreescalePowerQUICC processors, Marvell Orion,AMCC405 family ofPowerPC processors, and theIntelXScale IOP and IXP series.
The NetBSD cross-compiling framework (also known as "build.sh"[24]) lets a developer build a complete NetBSD system for an architecture from a more powerful system of different architecture (cross-compiling), including on a different operating system (the framework supports mostPOSIX-compliant systems). Several embedded systems using NetBSD have required no additional software development other than toolchain and target rehost.[25]
As of 2017, NetBSD had reached fullyreproducible builds onamd64 andSPARC64.[26] The build.sh-P flag handles reproducible builds automatically.
NetBSD featurespkgsrc (short for "package source"), a framework for building and managing third-partyapplication software packages. The pkgsrc collection consists of more than 29,000 packages as of September 2025[update].[27] Building and installing packages such asLumina,KDE,GNOME, theApache HTTP Server orPerl is performed through the use of a system ofmakefiles. This can automatically fetch the source code, unpack, patch,configure,build andinstall the package such that it can be removed again later. An alternative to compiling from source is to use a precompiled binary package. In either case, any prerequisites or dependencies will be installed automatically by the package system, without need for manual intervention.
pkgsrc is across-platform packaging system, for it supports not only NetBSD, but can be used on several otherUnix-like platforms, among whichmacOS,Solaris andLinux are considered primary targets.[28] OtherBSDs,HP-UX,Minix,SCO UNIX (Unixware andOpenServer) andQNX have a number of active pkgsrc users but do not receive active maintenance.
pkgsrc is the default package management system onSmartOS[29] and Minix3.[30] It was also previously adopted as the official package management system forDragonFly BSD,[31] and made available as an alternative packaging framework onMirBSD[32] and QNX.[33]
NetBSD has supportedSMP since the NetBSD 2.0 release in 2004,[34] which was initially implemented using thegiant lock approach.
During the development cycle of the NetBSD 5 release, major work was done to improve SMP support; most of the kernel subsystems were modified to use thefine-grained locking approach. Newsynchronization primitives were implemented andscheduler activations was replaced with a1:1 threading model in February 2007.[35][36] A scalable M2 thread scheduler was also implemented,[37] providing separate real-time (RT) and time-sharing (TS) queues, and improving the performance on MP systems. Threadedsoftware interrupts were implemented to improve synchronization. Thevirtual memory system,memory allocator andtrap handling were made MP safe. The file system framework, including theVFS and majorfile systems were modified to be MP safe. As of NetBSD 10.0, the only subsystems running with a giant lock areSATAdevice drivers,interrupt handlers, the autoconf(9) framework and most thenetwork stack, unless theNET_MPSAFE kernel option is enabled.[38]
In reality, starting with release 8.0, various parts of the network stack have been made MP safe already,[39] but NET_MPSAFE is kept disabled by default, because non-MP-safe components that are also unprotected by the giant lock may otherwise crash the kernel when loaded in memory.[40]
The 4.4BSD scheduler still remains the default, but was modified to scale with SMP, merging features from SCHED_M2.[41]In 2017, the scheduler was changed to better distribute load of long-running processes on multiple CPUs, and tunablekern.schedsysctl(3) parameters were introduced.[42] The release of NetBSD 10.0 brought significant performance enhancements, especially on multiprocessor and multicore systems;[43] the scheduler gained major awareness ofNUMA andhyperthreading, and became able to spread the load evenly across different physical CPUs, as well as to scale better on a mixture of slow and fast cores (e.g.ARM big.LITTLE).[44]
NetBSD supports a number of features designed to improve systemsecurity.[45] Some are listed below.
The Kernel Authorization framework[46] (or kauth) is a subsystem managing all authorization requests inside the kernel, and used as system-wide security policy. kauth(9) acts as a gatekeeper between kernel's own routines, by checking whether a givencall or a specific operation is allowed within the context, and returnsEPERM if not.[47] Most syscalls issue an authorization request in their correspondinghandler viakauth_authorize_action(). kauth also allows external modules to plug-in the authorization process.
Verified Executables (or Veriexec) is an in-kernel file integrity subsystem in NetBSD. It allows the user to setdigital fingerprints (hashes) of files, and take a number of different actions if files do not match their fingerprints. For example, one can allowPerl to run only scripts that match their fingerprints.[48]
Starting with version 2.0, NetBSD supportsnon-executable mappings on platforms where the hardware allows it.[49] Processstack andheap mappings are non-executable by default. This makes exploiting potentialbuffer overflows harder. NetBSD supportsPROT_EXEC permission viammap() for all platforms where the hardware differentiates execute access from data access, though not necessarily with single-page granularity.[50]
NetBSD implements severalexploit mitigation features, such asASLR (in both userland and kernel[51][52]), restrictedmprotect() (W^X) and Segvguard from thePaX project, andGCCStack Smashing Protection (SSP, or also known as ProPolice, enabled by default since NetBSD 6.0) compiler extensions.
The cryptographic device driver (CGD) provides transparentdisk encryption by acting as alogical device that is layered on top of another block device, such as a physical disk or partition (includingCDs and DVDs) or a vnd(4)pseudo device.[53] It supports theAdiantum cipher, besides AES in CBC/XTS modes.[54]
NPF, introduced with NetBSD 6.0,[55] is alayer 3 packet filter, supportingstateful packet inspection,IPv6,NAT, IP sets, and extensions.[56] It usesBPF as its core engine, and supportsbpfjit. NPF was designed with a focus on high performance, scalability, multi-threading and modularity.
Relevant to security are also BSDsecurelevels,[57] blocklistd(8), a daemon capable of blocking ports on demand to avoidDoS abuse,[58] and the wg(4) interface, which provides a homegrown implementation of theWireGuard protocol.[59]
The NetBSD code is regularly scanned for bugs, and security advisories — containing a pointer to the fix — are published on the official mailing lists.[60]
NetBSD uses theUVM[61]virtual memory system, developed by Charles D. Cranor at Washington University in 1998, and committed to the NetBSD source tree by Matthew Green, who handled integration issues and wrote theswap subsystem.[62]
The originalMach based4.4BSD system[63] was replaced by UVM in NetBSD 1.4.[64] UVM is designedto reduce the complexity of the 4.4BSDVM system, and offer improved performance for those applications which make heavy use of VM features, such asmemory-mapped files andcopy-on-write memory.[65]
While retaining the same MD/MI layering and mapping structures of the BSD VM,[66] UVM introduces some noticeable changes:
Memory objects are allocated and managed in cooperation with their backing data source (typicallyvnodes), reducing the overhead of thevm_object chain management. Thevm_pagestructure describes how the backing store can be accessed. Essentially, this is a pointer to a list of functions which act as bridge between UVM and the external backing store (such as a disk) that provides UVM with its data. UVM's memory object points directly to thepager operations, making the allocation of pager-relateddata structures more efficient.
Anonymous pages are grouped in multi-page clusters forpageout. Eachpage's location on swap is assigned, so that the cluster occupies a contiguous chunk of swap and can be paged out in a single largeI/O operation. This enhances paging response time for I/O operations, and allows UVM to recover quicker from page shortages.
Memory sharing is supported using three data movement mechanisms:page loanout,page transfer, andmap entry passing.[67] Aprocess may safely let a shared copy-on-write copy of its memory be used either by other processes, the I/O system, or theIPC system. Theunified buffer cache (ubc(9)[68] ), written by Chuck Silvers, allows to use UVM pages tocache vnode data rather than the traditional UNIX buffer cache.[69] This avoids costly data copies, and makes more memory available for caching regular file data.
In 2003, UVM was modified to use a top-down memory management, thus merging the space reserved forheap growth and the area of space reserved formmap(2)'ed allocations.[70] This allows the heap to grow larger, or a process to mmap more or larger objects.
Support for RAMhot-plugging was added in 2016.[71] The uvm_hotplug(9) API replaces the previously exposedvm_physmem static array with ared–black tree backing to keep track of memory segments, allowing the list of physical pages to be dynamically expanded or collapsed.
During the release cycle of NetBSD 10.0, major work was done to optimize the virtual memory system.[72] The page allocator was rewritten to be more efficient and CPU topology aware, adding preliminaryNUMA support. The algorithm used in the memory page lookupcache was switched to a fasterradix tree. Tracking and indexing of clean/dirty pages was improved, speeding upfsync(2) on large files by orders of magnitude.Lock contention was reduced by making the maintentance of page replacement state more concurrent.
TheXenvirtual-machine monitor has been supported in NetBSD since release 3.0. The use of Xen requires a special pre-kernel boot environment that loads a Xen-specialized kernel as the "host OS" (Dom0). Any number of "guest OSes" (DomU) virtualized computers, with or without specific Xen/DomU support, can be run in parallel with the appropriate hardware resources.
The need for a third-partyboot manager, such asGRUB, was eliminated with NetBSD 5's Xen-compatible boot manager.[73] NetBSD 6 as a Dom0 has beenbenchmarked comparably to Linux, with better performance than Linux in some tests.[74]
As of NetBSD 9.0, accelerated virtualization is provided through the native type-2hypervisor NVMM (NetBSD Virtual Machine Monitor).[75]It provides a virtualization API,libnvmm, that can be leveraged by emulators such asQEMU.[76][77]The kernel NVMM driver comes as a dynamicallyloadable kernel module, made of a generic machine-independent frontend, to which machine-dependent backends can be plugged to implement the core virtualization (currently onlyx86 AMD SVM and Intel VMX are supported).[78] A unique property of NVMM is that the kernel never accesses guest VM memory, only creating it.[79]Intel'sHardware Accelerated Execution Manager (HAXM) provides an alternative solution for acceleration in QEMU for Intel CPUs only, similar to Linux'sKVM.[80]
NetBSD 5.0 introduced the rump kernel,[81] an architecture to run drivers in user-space by emulating kernel-space calls. A rump kernel can be seen as a lightweight, portable virtualized driver execution environment, characterized by smallmemory footprint and minimizedattack surface.[82]
The core of a rump kernel contains a set of fundamental routines which allow it to access the host platform's resources, such asvirtual memory, threadscheduler andI/O functions. This is called the rampuser(3) hypercall interface.[83] The various kernel subsystems (e.g.TCP/IP stack, filesystems, hardwaredevice drivers), globally referred asdrivers, are layered on top of the hypercall interface, by being linked against a stripped-down version of the NetBSD kernel that can be executed in user mode. Most drivers are optional, and may be included or not depending on the target application and scope.
This "anykernel" design allows adding support of NetBSD drivers to other kernel architectures,[84] ranging fromexokernels tomonolithic kernels.[85] Other possible applications of rump kernels include deploying a task-specificunikernel to provide aPOSIX API for application depending on it, running a self-containeddatabase with minimal footprints,[86] a userspaceWireGuard instance,[87] editing the contents of a file system as unprivileged user, and segregating a web browser to its own TCP/IP stack.[88]
Rump kernels are also used internally by the NetBSD project for running tests on different kernel subsystems, as well as fordebugging purposes.[89]
Thebio(4) interface for vendor-agnosticRAID volume management throughbioctl has been available in NetBSD since 2007.[90]Support forsoftware RAID is provided as a port of CMU RAIDframe, available since NetBSD 1.4.[91]The ccd(4) driver provides the capability of combining one or more disks/partitions into one virtual disk, acting as another in-kernel RAID 0 subsystem.[92]
UFS2, an extension to BSDFFS adding 64-bit blockpointers, variable-sized blocks (similar toextents), and extended flag fields, was ported from FreeBSD in 2003[93] and made available since NetBSD 2.0.[94] The fss(4)[95]snapshot driver was introduced the same year,[96] allowing to create a read-only, atomic view of a FFS filesystem at a given point of time; a FFS snapshot works as aspecial device, which can be mounted and used in conjunction with utilities likedump(8) to create and export systembackups.[97]
WAPBL, a FFS filesystem extension providing data journaling, was contributed by Wasabi Systems in 2008.[98] Journaling allows rapid filesystem consistency after an unclean shutdown, and improves write performance by reducing synchronousmetadata writes, especially when creating a large number of inodes.[99] Support forsoft updates on NetBSD FFS(v1/2) was eventually removed in favor of WAPBL.[100]
TheZFS filesystem developed bySun Microsystems was imported into the NetBSD base system in 2009.[103] In 2018, the ZFS codebase was updated and rebased onFreeBSD's implementation.[104] ZFS was finally marked safe for daily use in NetBSD 9.0.[105] As of 10.0 release, NetBSD ZFS stack is comparable to that of FreeBSD 12 (or below), with ZFS filesystem version "5.3", zpool version "5000" (some feature flags are not supported).[106][107] Native ZFS encryption is noticeably missing, though a zpool may be created within a cgd(4) encrypted disk.[108]Initial support for ZFSroot is available, but neither integrated in the installer nor in the bootloader.[109]
The NetBSD Logical Volume Manager is based on a BSD reimplementation of a device-mapper driver and a port of the LinuxLogical Volume Manager tools. It was mostly written during theGoogle Summer of Code 2008.[110]
TheCHFSFlash memory filesystem was imported into NetBSD in November 2011. CHFS is a file system developed at the Department of Software Engineering,University of Szeged,Hungary, and is the first open source Flash-specific file system written for NetBSD.
ThePUFFS framework, introduced in NetBSD 5.0,[111] is a kernel subsystem designed for running filesystems in userspace, and provides FUSE kernel level API compatibility in conjunction with the perfused(8) userland daemon.
Atmpfs implementation for NetBSD using conventional in-memory data structures, was first developed by Julio M. Merino Vidal in 2005 as aGSoC project,[112] and merged the same year in the NetBSD source tree.[113]
At the source code level, NetBSD is very nearly entirely compliant withPOSIX.1 (IEEE 1003.1-1990) standard and mostly compliant with POSIX.2 (IEEE 1003.2-1992).
NetBSD providessystem call-level binary compatibility on the appropriate processor architectures with its previous releases, but also with several otherUNIX-derived and UNIX-like operating systems, includingLinux, and other 4.3BSD derivatives likeSunOS 4. This allows NetBSD users to run many applications that are only distributed in binary form for other operating systems, usually with no significant loss of performance.[114] Initial support for aHaiku binary compat layer was published on the netbsd-user mailing list.[115]
WINE can be installed on NetBSD throughpkgsrc.[116] Kernel support forUSER_LTD — required forWoW64 — was contributed by Maxime Villard in 2017,[117] allowingWin32 applications to be executed onamd64.[118] The amd64 port of wine for NetBSD was completed by Naveen Narayanan as part ofGSoC 2019.[119]
Kernel-space scripting with theLua programming language was added in NetBSD 7.0.[120] The Lua language (i.e., its interpreter and standard libraries) was initially ported by Lourival Vieira Neto to the NetBSD kernel duringGSoC 2010 and has undergone several improvements since then.[121] The Lua (userspace) Test Suite was ported to NetBSD kernel Lua during GSoC 2015.[122]
There are two main differences between user and kernel space Lua: kernel Lua does not supportfloating-point numbers; as such, only Lua integers are available.[123] It also does not have full support to user space libraries that rely on the operating system (e.g.,io andos). A sample implementation ofI/O (file systems andsockets) bindings for kernel Lua was developed by Guilherme Salazar.[124]
Possible applications of the Lua kernel interpreter include embedding extensions for theNPF packet fiter,[125][126] and building an in-kernel application sandbox based on kauth(9), with sandbox policies provided as Lua scripts.[127]
NetBSD provides a minimalistkernel debugger — DDB(4) — which is invoked by default whenever the kernel would otherwise panic.[128] DDB allows to inspect processes and threads, investigatedeadlocks, get astack trace, and generate a kernelcrash dump for later analysis.[129]
Strict consistency check is enabled by building the kernel with optionDIAGNOSTIC. This will cause the kernel to panic if corruption of internal data structures is detected (e.g. kernel NULL pointer dereference).[130]
NetBSD also supports a variety of in-kernel bug detection facilities,[131] includingcode sanitizers (undefined behavior, address, thread, memory sanitizers),[132][133] a kernelmemory disclosure detection system (KLEAK)[134] and a kernel diagnostic subsystem named heartbeat(9).[135]
Loadable kernel modules have been supported on NetBSD since 0.9. The original lkm(4) interface[136] written by Terry Lambert was replaced by the new modules(7) subsystem,[137] which supports dependency handling between modules, and loading of kernel modules on demand.[138]
New modules can only be loaded when securelevel is less than or equal to zero, or if the kernel was built with options INSECURE, due to security concerns regarding the lack of memory protection between modules and the rest of the kernel.
Every kernel module is required to define its metadata through the C macroMODULE(class, name, required) and to implement aMODNAME_modcmd function, which the kernel calls to report important module-related events, like when the module loads or unloads.[139]
Support for using aninitial ramdisk is available but not enabled by default,[140] except for specific configurations (e.g. rootencryption).[141]
The rc.d(8) framework, designed by Luke Mewburn[142] for NetBSD 1.5,[143] provides a fully modular service management system, using individualshell scripts for controlling services, similar to whatSystem V does, but withoutrunlevels.[144] When/etc/rc/ is invoked by init(8), it executes scripts located in the/etc/rc.d directory. The order in which scripts are executed is determined by the rcorder(8) utility, based on the requirements stated in the dependency tags found within each script.[145]
NetBSD has featured a nativehardware monitoring framework since 1999/2000. In 2003, it served as the inspiration behind theOpenBSD's sysctlhw.sensors framework when some NetBSD drivers were being ported to OpenBSD.[146]
As of March 2019[update], NetBSD had close to 85 device drivers exporting data through the API of the envsys framework. Since the 2007 revision, serialization of data between the kernel and userland is done through XMLproperty lists with the help of NetBSD'sproplib(3).
The NetBSD audio(4)[147] kernel API, modelled afterSunOS sound stack (SADA),[148] provides at the same time a uniform programming interface layer above different underlying audio hardware drivers, and backend for different sound libraries (SDL,PortAudio, Mozilla cubeb) to use.
Applications may interact with the/dev/audiodevice node directly, using a series ofioctls specified in thesys/audioio.h header file. Audio device information may be queried with theAUDIO_GETDEV ioctl. Playing and recording sound implies opening/dev/audio forread() /write() operations and passing anaudio_infostruct to the kernel. This results in reducedaudio latency and CPU usage compared to using additional abstraction layers (other sound libraries and/orsound servers).[149]
The audio stack was reworked in NetBSD 8.0 to provide an in-kernel softwaremixing engine, with support for virtual channels;[150] this allows more than one process to play or record audio at the same time.
A compatibility mode for theOSS API is provided by thesoundcard.h header file and thelibossaudio library,[151] which internally operate using the native Sun-like audio interface.
NetBSD includes built-inMIDI support through the machine-independent midi(4)[152] system.
Dell Force10 uses NetBSD as the underlying operating system that powers FTOS (the Force10 Operating System), which is used in high scalability switch/routers.[166] Force10 also made a donation to the NetBSD Foundation in 2007 to help further research and the open development community.[167]
Several companies are known to use NetBSD internally:
Wasabi Systems[178] provides a commercial "Wasabi Certified BSD" product based on NetBSD[179] with proprietary enterprise features and extensions, which are focused on embedded, server and storage applications. Wasabi has a long history of cooperation with the NetBSD project, including the development ofWAPBL[180] andPCI storage devicespowered by NetBSD.[181]
Precedence Technologies[182] offersthin-client software (ThinIT) and accompanying hardware based on NetBSD.[183]
Internet Initiative Japan, Inc. (IIJ) sellsCPErouters commercialized as "SEIL",[184] which run a modified version of NetBSD at their core, and operate through a proprietary network management system (SMF) also based on NetBSD.[185] The SEIL/X4 has 2xGE ports (WAN,DMZ), 4x GEL2 switch ports, 2xUSB 2.0 ports, and reaches a throughput of 2Gbps, andVPN rate of up to 2 Gbit/s.[186]
Moritz Systems, an EU-based IT company specialized in embedded systems,IoT,edge computing andquality audits, also bases its products on NetBSD.[187]
TDI Security,[188] a US company specialized incybersecurity, offers portableSAN andVPN solutions (named "pocketSAN" and "pocketVPN" respectively), designed to be run from a USB thumb-drive or an embedded device, and built upon a minimalist deployment of NetBSD installed onflash memory ("polyBSD").[189]
TheNPF packet filter has been used in commercial products such as Outscale[196] and BisonRouter.[197]
NetBSD's owncurses implementation[198] is used by Sabotage Linux.[199]
Rump kernels have been integrated in other operating systems to provide additional functionality:
Genode OS Framework; uses a rump kernel to support various files systems, both as a standalone FS server (rump_fs) and as a library plugin for its modularVFS (vfs_rump.lib.so).[200][201]
GNU Hurd; implements multiple rump kernel deployments to get moderndevice drivers, ranging from storage device drivers (RumpDisk), to sound devices drivers (RumpSound), and drivers forEthernet/WLAN controllers (RumpNet).[202]
TheSDF Public Access Unix System, anon-profit public accessUNIXshell provider with the aim to provide remotely accessible computing facilities, uses NetBSD to power its infrastructure.[204] With a network of eight 64-bit enterprise class servers running NetBSD, and realising a combined processing power of over 21.1GFLOPS (2018),[205] the SDF.org cluster is considered the largest NetBSD installation in the world, factually working as a testbed for future NetBSD releases.[206]
All of the NetBSD kernel and most of the core userland source code is released under the terms of theBSD License (two, three, and four-clause variants). This essentially allows everyone to use, modify, redistribute or sell it as they wish, as long as they do not remove the copyright notice and license text (the four-clause variants also include terms relating to publicity material). Thus, the development of products based on NetBSD is possible without having to make modifications to the source code public. In contrast, theGPL, which does not apply to NetBSD, stipulates that changes to source code of a product must be released to the product recipient when products derived from those changes are released.
On 20 June 2008, the NetBSD Foundation announced a transition to the two clause BSD license, citing concerns with UCB support of clause 3 and industry applicability of clause 4.[208]
NetBSD also includes theGNU development tools and other packages, which are covered by the GPL and other open source licenses. As with otherBSD projects, NetBSD separates those in its base source tree to make it easier to remove code that is under more restrictive licenses.[209] As for packages, the installed software licenses may be controlled by modifying the list of allowed licenses in the pkgsrc configuration file (mk.conf).
Support for newAArch64 security features: Privileged Access Never, Pointer Authentication, Branch Target Identification. Support forLinux binary compatibility on AArch64.
Support for PVHXen virtualization,paravirtualization and multiprocessor Dom0 support in Xen
SMP support forXen domU kernels, initial suspend/resume support for Xen domU, PCI pass-through support for Xen3, and addition of the balloon driver
Major rework ofMIPS port adding support forSymmetric multiprocessing and 64-bit (O32, N32, N64 ABIs are supported) processors, DSP v2 ASE extension, various NetLogic/RMI processor models,Loongson family processors, and newSoC boards
Improved SMP onPowerPC port and added support for Book E Freescale MPC85xx (e500 core) processors
RewrittenLoadable kernel module framework, which will replace old LKMs. Use ofX.Org rather thanXFree86 by default for i386 and amd64 ports, and introduction of drm(4)/DRI for 3D hardware acceleration. Preliminary support for usingClang instead of GCC as the system compiler.[219]
Added support forASLR in the kernel and dynamic linker.
Rewrittenenvsys framework (envsys2); addition of 8 new Hardware Monitoring sensor drivers; newI2C attachment of the lm(4) driver; additional hardware support in several sensor drivers[216]
The legally encumbered Net/2-derived source code was replaced with equivalent code from 4.4BSD-lite, in accordance with theUSL v BSDi lawsuit settlement.
The first official release, derived from386BSD 0.1 plus the version 0.2.2 unofficial patchkit, with several programs from the Net/2 release missing from 386BSD re-integrated, and various other improvements.[230]
The NetBSD "flag" logo, designed by Grant Bissett, was introduced in 2004 and is an abstraction of the older logo,[231] which was designed by Shawn Mueller in 1994. Mueller's version was based on the famousWorld War II photographRaising the Flag on Iwo Jima.[232]
The NetBSD Foundation is the legal entity that owns the intellectual property and trademarks associated with NetBSD,[233] and on 22 January 2004, became a501(c)(3) tax-exempt non-profit organization. The members of the foundation are developers who have CVS commit access.[234] The NetBSD Foundation has a Board of Directors, elected by the voting of members for two years.[235]
Hosting for the project is provided primarily byColumbia University, andWestern Washington University, fronted by aCDN provided byFastly. Mirrors for the project are spread around the world and provided by volunteers and supporters of the project.
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