Here is the matheval Subversion page.
To checkout the code from the repository use the following command:
$ svn co https://svn.sourceforge.net/svnroot/matheval/trunk [path][path] is the path to where you want the code to be. For the current directory, use '.'. Note that the protocol is https. Anyone can checkout and read from the repository, but committing code is reserved for EuSQL developers.
You can also browse the repository through the web.