No it isn't. I use and like the app also, but the GitHub repo link on their page takes you to a separate release artifact management repo, not the source code itself.

> https://getfancontrol.com/

Their linked GitHub repo, which only has a compiled zip uploaded for release artifact creation, not the code:

> https://github.com/Rem0o/FanControl.Releases

From the repo:

"Sources for this software are closed."

I wonder why the author hasn't open sourced it - there doesn't appear to be any commercial aspect to the tool, and the author makes a point of it being "free" on the site.