Maxima is pre-packaged for most linux distributions. It runs under linux, mac OS X, MS Windows.
Here is the software and documentation, etc. You need to get Maxima separately. Following are downloads for unix/linux and Windows. They both have exactly the same contents, but one is in zip format and the other in tar format. Mac OSX can probably unpack either of them. The program files are packed separately from the documentation. So you need to download the program files and at least one of the documentation packages. The documentation is available in pdf or html format. The html is available as one long page, or broken into several web pages. The html is available with links to the Maxima manual at the Maxima website, or with links to a local copy of the Maxima manual which is included in the package. The later is more convenient, but requires a 5 MB disk space.
The package is under development, with those features useful to me being implemented first. A partial list of features:
You can send comments or questions to website "at" the same
domain name as this page if you don't have my address.
Until I found the list, I was uncovering the packages slowly, as they are not very well publicized. But some seem to be very good packages. I have not been able to try any of them yet, as I don't have easy access to the CAS's that they require. As far as I know, the package on the present page Qinf is the only one that does not require a proprietary computer algebra system.