Mono is a portable and open source implementation of the .NET framework for Unix, Windows, MacOS and other operating systems.
Mono 2.10.4 is a minor update to Mono 2.10, Mono 2.10.1, Mono 2.10.2, Mono 2.10.3 based on the mono-2-10 branch of github. Mono 2.10.4 was released on August 9th, 2011.
For more information on changes since Mono 2.10, you can also read the release notes for Mono 2.10.1, Mono 2.10.2 and Mono 2.10.3.
This release fixes a regression in the XmlSerializer that was introduced in Mono 2.10.3 and fixes a packaging issue for IronPython on MacOS X.