It depends on type of analysis you want to do. As Hiqmet Kamberaj said there are couple of packages with analysis toolbox to do some general analysis. But if you are looking for advance analysis or higher performance there are numerous projects on "google project" you can use. If you have any specific thing in mind I can help.
To be frank, depends on what kind of analysis. May be post the list of analyses that you intend to perform, the members of forum may be able to suggest the best tool in each case. But gromacs, has lot of in-built analyses tools, so the chances of finding what you might need is very high, provided we understand what the script does and choose a suitable index accordingly.