With all the recent heat generated about Mono and the C# language, it only seems appropriate to take a look at the issue from a programmer's perspective. There are a number of open source projects written in the C# language. Banshee, F-Spot and Tomboy are three of the most popular. F-Spot has even made it to the status of default photo management tool for several distributions including openSUSE and Ubuntu.
GNOME Do is a great example of open source software that started out as the pet project of one individual. In actuality, it began as the senior thesis project for David Siegel. David needed to come up with an idea for a software project that would embrace the development concepts of the open source community. Having most of his experience in the Mac world, he decided on building a Quicksilver lookalike for Linux.
David had made the initial decision to build his tool for the GNOME desktop environment on Ubuntu. He looked at a number of different languages including C, Python, Vala, Java, Boo, Haskell, Clojure, and OCaml. The decision to use C# came through a process of elimination. Here's how he answered the language question in response to a post on his blog:
"I implemented basic Gtk+ examples in most of those languages (the ones that had Gtk+ bindings in a reasonable state) and found that C# on Mono gave me a statically typed language, pretty good performance, tons of support, preexisting applications to learn from, well maintained documentation, bindings, and libraries, and published books on .NET/C#/Mono."
The Mono group also has a lively IRC channel where you will