A press release here tells of cross-platform support for Visual Studio.
http://www.mainsoft.com/press/pr-vstudio.html?la712

A familiar name appears in the second paragraph:

“We are excited to work closely with Mainsoft through the Visual Studio Integration Program,” said Robert Green, Visual Studio lead product manager at Microsoft Corp. “MainWin provides a great Visual Studio cross-platform solution and helps customers support their code on UNIX and Linux.”