Current release 2012-02-08: MrBayes 3.2.1
All downloads of MrBayes are now managed through the MrBayes download page on SourceForge. You can download executable versions for Windows(32bit), Windows(64bit) and Macintosh(64bit) computers, as well as the source code for compilation on Unix machines. SourceForge allows you to download from a mirror site close to you and helps us collect some basic statistics about the downloads. Refer to the User Manual for help with installation of the program. Note that on 64bit Windows OS you can install simultaneously and run both 32 and 64 bit versions of MrBayes. 32 bit version may not be able to handel large datasets, but it may be marginaly faster than 64 bit version.
You can get access to older releases from here.
You may also download cutting edge developer version of MrBayes from svn repository hosted at sourceforge. Note that you have to compile the code yourself. Read instructions in README.txt file in the root directory of svn repository for further instructions.
A great aid for resolving problems with MrBayes is the MrBayes
If you have a question about MrBayes you can ask it by posting the question to the mailing list. To post on this list you
have to be subscribed to it. However, the list archive
is accessible to everyone.
The list will also be used by the MrBayes authors for announcements about new versions or bugfixes.
We, therefore, highly recommend that you subscribe to the list if you are a regular MrBayes user.