@mpdude and@derrabus feel free to add commits to this PR

Just for the record, I've talked about this at the Symfony User Group Cologne back in 2013. Unfortunately, slides are in German and of limited use without the sound track:

https://www.slideshare.net/webfactory/marry-me-public

Additionally, we've published thehttps://github.com/webfactory/WebfactoryLegacyIntegrationBundle back then and since used it successfully on several legacy systems.

My talk is from 2016 which in itself is somewhat legacy now. ;-)

• https://slidr.io/derrabus/modernizing-with-symfony
• https://www.youtube.com/watch?v=YzyiZNY9htQ

@weaverryan@javiereguiluz I'm also interested to know your opinion about this article. We shortly discussed this at EU-FOSSA and came up with this idea to explain some general ideas on how to migrate from legacy code to Symfony in the documentation.

As it's all very specific to the project, we can't document one approach that works for all. But showing some approaches (from the least to most radical) can imo be a nice addition for projects facing this problem.

Thanks for your feedback@javiereguiluz and everyone else :)
I am happy with the current state and think this is ready to be merged.

@dbrumann I'd like to do another review on the weekend, if that's okay for you.

What do you say, is this ready to be merged?@OskarStark,@javiereguiluz

Yes but this should go into 4.2 instead of master IMHO

I rebased and changed the target branch to 4.2

Hi@dbrumann! Thanks a lot of the huge effort put into this PR!!

As I wasn't able to review your PR anywhere soon after you created it, I've merged it directly and did a proof-read and changes afterwards. You can see all these changes indb82d54. It's mostly structuring the "Prerequisites" section a bit and some minor clearifications/breaking long sentences/paragraphs.

Again thanks and also thanks to@derrabus for closely reviewing this one!