TheDeveloper Transition Kit is the name of two prototypeMac computers made available to software developers byApple Inc. The first Developer Transition Kit was made available in 2005 prior to theMac transition to Intel processors to aid in the Mac's transition fromPowerPC to an Intel-basedx86-64 architecture. A second Developer Transition Kit was made available in 2020 prior to theMac transition to Apple silicon as part of its initiative to transition the Mac away from Intel to Apple'sARM64-basedApple silicon.

During Apple's 2005–2006transition from PowerPC to Intel processors, the company made available the first Developer Transition Kit (DTK), a prototype Intel-based Mac computer for developers.

During Apple's 2005 Worldwide Developers Conference, then-CEOSteve Jobs emphasized the non-commercial nature of the prototype hardware: "This is a development platform only. This is not a product; this will never be shipped as a product. It's just for you guys to get started in development. You actually have to return them by the end of 2006. We don't want them floating around out there. These are not products."^[1]

The computer identified itself as "Apple Development Platform" (ADP2,1), and consisted of a 3.6 GHz IntelPentium 4 Prescott 2M 660^[2] processor, 1 GB DDR2 RAM, 160 GB SATA hard disk drive, and optical disk drive in aPower Mac G5 case slightly modified with an altered cooling system. Connectivity included USB 2.0, FireWire 400, and Gigabit Ethernet. Software includedXcode 2.1 and a version ofMac OS X 10.4.1 which runs on Intel'sx86 architecture.^[3][1]

The Intel DTK was available to software developers on a loan basis, and Apple required developers to return the prototype computers to the company within a week of December 31, 2006.^[3][4] Apple required developers to be aSelect or Premier Apple Developer Connect (ADC) member, with memberships starting atUS$499 per year and additional requirement to payUS$999 to receive an Intel DTK.^[5] Apple then offered developers a free Intel-based iMac in exchange for sending back the DTK.^[6] The Intel DTK would be directly succeeded by the first-generationMac Pro.

At theWorldwide Developers Conference, on June 22, 2020, Apple announced another Developer Transition Kit intended to assist software developers during thetransition of theMac platform to theARM architecture.^[7] Described informally as "aniPad in aMac mini's body,"^[8] the DTK carries a model number of A2330 and identifies itself as "Apple Development Platform."^[4][9] It consisted of anA12Z processor, 16 GBRAM, 512 GBSSD, and a variety of common I/O ports (USB-C, USB-A,HDMI 2.0, andGigabit Ethernet) in a Mac mini case.^[7][4][10] Support for wireless communication based uponWi-Fi 5 (802.11ac) andBluetooth 5.0 was included, whileThunderbolt 3 support, built-in to every Mac commercially available as of June 2020, was not included.^[11] It eventually appeared in the first three models of Apple silicon Macs, operating in Thunderbolt 3/USB4 mode. The DTK came preloaded withbeta versions ofmacOS 11 Big Sur. The A12Z DTK would be directly succeeded by the2020 Mac mini with theM1 chip.

In an interview shortly after the introduction of the DTK, Apple's SVP of Software EngineeringCraig Federighi praised the DTK's performance and contributed to expectations of superlative performance of forthcoming commercial products based upon Apple silicon custom-engineered for the Macintosh platform: "Even that DTK hardware, which is running on an existing iPad chip that we don't intend to put in a Mac in the future – it's just there for the transition – the Mac runs awfully nice on that system. It's not a basis on which to judge future Macs ... but it gives you a sense of what our silicon team can do when they're not even trying – and they're going to be trying."^[12][13]

To receive a DTK, developers were required to sign up for a one year membership to Apple's Universal App Quick Start Program at a cost ofUS$500.^[14][7]The membership included several benefits such as code-level technical support, access to one-on-one labs with Apple engineers, and a license to use a loaned DTK.^[15]

The device had to be returned to Apple one year after joining theUniversal App Quick Start Program, "or as otherwise earlier requested by Apple."^[16] Several conditions of use were attached, including restrictions against disassembling the computer, running unauthorized benchmark tests, or using it for work other than transition-related software development.^[4][16]

The terms of the Universal App Quick Start Program indicated that the program would run for the duration of one year counted from the moment the developer signed up for it, with an option to terminate it early without reason. Additionally, it had a specific provision regarding one of the benefits associated with the program, namely the DTK. The DTK was to be returned within 30 days after the end of the program itself or "as otherwise earlier requested by Apple".^[16] Apple had earlier communicated that the DTK was meant to prepare for the launch of Macs based onApple silicon, thereby suggesting that the Program would be available until the new Apple silicon Macs would be available.

In February 2021 Apple emailed the developers regarding the early return of the DTK while keeping the rest of the program and its benefits active until the original expiration of one year.^[17] Additionally, Apple indicated in their email that they would provide a discount code for aUS$200 discount towards the purchase of a Mac withM1 after the DTK was returned. This discount code wasn't promised beforehand or part of the original agreement but was considered as a compensation in exchange of an early return.^[17]

Some developers reacted with criticism to the email. Among them were developers that voiced their unhappiness about their experience with the DTK. Apple wrote in the description of the Program that the "Developer Transition Kit [was] not fully tested and [was] to be used only for limited testing and development purposes" and that the DTK "may contain errors that could cause failures or loss of data". However developers complained that the DTK was showing much more issues than a normal user would've expected, making it "unusable" in development.^[17][16] Others were under the impression that they could use the DTK for a full year, being caught in surprise by Apple's email indicating that they soon had to return the DTK.^{[citation needed]} Many were also indicating that they were unhappy about theUS$200 discount code offered by Apple, comparing it to when Apple unexpectedly offered developers the option to return theirIntel DTK earlier than the originally planned date for an iMac duringthe transition from PowerPC to Intel processors. During the last transition, a developer could also choose to keep the DTK for the whole length of the program except that they would not get the iMac.^[17]

On February 5, 2021, following developer backlash, Apple sent out another email that increased the discount code to US$500 and expanded the discount to be used on any other Apple devices. In addition, the code expired at the end of 2021, instead of May.^[18]

• Apple's announcement of DTK introduction as part of Mac transition to Apple silicon
• Official technical specifications

• X86 Macintosh computers
• ARM Macintosh computers
• Computer-related introductions in 2005
• Computer-related introductions in 2020

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• Short description is different from Wikidata
• All articles with unsourced statements
• Articles with unsourced statements from February 2021