Few days ago Howard Dierking from Microsoft has recently published a short note on his blog (http://codebetter.com/howarddierking/2013/07/23/katana-license-lifts-windows-only-restriction/) - seems not a big deal, isn’t it? Well, in this case it’s more than just interesting, because:

  • Howard and his gang work on "Katana" project (that is interesting itself)

  • It’s (the post I mean) about lifting one of the fundamental ramparts of Microsoft software toolset production strategy - OS exclusivity

To the point:

In shortest possible words (forgive the simplification then) - "Katana" is a reference implementation (it took this role after project "Gate" has been abandoned - https://github.com/owin/gate) of OWIN standard.

What’s OWIN (Open Web Interface for .NET)? It’s an interface between generic web server and the web applications that are supposed to run on it. It’s meant to remove the dependency of web servers on frameworks and other application platform-specific components (http://owin.org/). OWIN’s specification authors admit to find their inspiration in project Rack (http://rack.github.io/) for Ruby.

So, what’s so special about OWIN and "Katana"? It’s supposed to let you mix various web applications (regardless of tech beneath) on a lightweight, scalable and generic platform - and it doesn’t matter if you deploy on premise or in the cloud, on dev machine or on production machine, etc.

As long as you do it on Windows. Well, until now.

As you’ve probably already seen, "Katana" is an OSS project (that’s a new trend in Microsoft for a year or something), but majority of such projects are limited (due to license used) “to run only on Windows platform”. And this restriction is now lifted (just for "Katana", but well, it’s better than nothing), so you can use it for instance on Mono.

It’s a nice contradiction to traditional differentiation between JVM and .NET world - Java programs were running on any OS (but until recently they were written in just 1 language - Java) and .NET programs may have been written in multiple languages, but they were limited to Windows OS (to make sure MSFT gets their dinero for its license).

However OSS world doesn’t like such limitations - it rebels against any tries of monopolizing technology / platform / service. And Microsoft seems to have finally noticed that. Time to grab popcorn and see what happens next …

If you want to learn more about OWIN and "Katana", here are some nice links:

P.S. “Reference implementation”. “Reference”. “REFERENCE”. “R-E-F-E-R-E-N-C-E”. In your face, OATH. Learn that. :)