It took a court battle to force Microsoft to hand over the protocol documentation to the Samba project.
As Linux is gaining popularity Microsoft seems to have increased its contribution to ensure their products will work well with Linux. The recent patch submission to the Linux kernel was an indicator.
The submission of some patches to the Samba project is a move in the same direction.
Stephen Zarkos of the Microsoft Open Source Technology Centre wrote on the Samba mailing list, "Earlier this year we had an intern working with us to implement a proof of concept for extended protection (channel and service binding) for Firefox and Samba."
The submission meets appreciation from the Samba project. Chris Hertel of Samba team writes, "...you may have noted a patch submission that came in on October 10th, 2011. As often happens, a couple of developers at a company found a way to improve core Samba code. They got permission to submit the patches under their own copyright and the terms of the GPL, and they sent the patches in.
It happens all the time in Samba, and we are always grateful. The only notable thing in this particular case is the company for which those developers work: Microsoft."
He also pointed at the rocking relationship with Microsoft:
A few years back, a patch submission from coders at Microsoft would have been amazing to the point of unthinkable, but the battles are mostly over and times have changed. We still disagree on some things such as the role of software patents in preventing the creation of innovative software; but Microsoft is now at the forefront of efforts to build a stronger community and improve interoperability in the SMB world.
What remains true is most often maintainers never know the source of the contribution unless the developer is using company signature in the mail or using the company email ID.
Chris further writes, "...but some of us saw this as a milestone, and wanted to make a point of expressing our appreciation for the patch and the changes we have seen."
The Samba project only recently started allowing patch submissions from corporate entities.