There have been a seemingly endless stream of incidences of him shilling for MS, going on for several years now. The two most common themes of shilling are trying to push Mono as a viable linux technology, trying to push Mono as a dependancy on common linux systems, and shilling for OOXML like you see here.

Another (slightly less common) theme is his ad hominem attacks on [F]OSS figures/organizations/supporters such as the FSF and Groklaw, like you see here.

He's been at this for years, it's no stretch of an imagination to call it a "long history".

Mono is viable Linux technology. You probably should learn what the word "shill" means before continuing further.

While investigating the word "shill", a refresher on "ad hominem" would help, too, as the submitted blog entry is not an example of an ad hominem.

What's wrong with pushing Mono as a viable linux technology?

     trying to push Mono as a dependancy on common linux systems

Wishing for $PROJECT's popularity while choosing to work on $PROJECT out of passion for many years?

I'm shocked, shocked I tell you!

     ad hominem attacks on [F]OSS figures/organizations/supporters 

Because [F]OSS figures are very civilized and have in no way attacked Miguel countless times and will never do so?

Again, I'm shocked that Miguel doesn't just bend over and take it like a chump.

Mono is a viable linux technology.