Files can be downloaded from the Files section in the Sourceforge site. That section contains links to various different versions and releases of Maxima.
The section Recent Releases (on the right or at the bottom of this page) shows the most recent releases and clicking on a release number will show the Change Log for it.
Get the most recent version from the Maxima-Windows subsection, which will be a single file with a self-contained installer program.
Normally linux distributions include a packet manager that allows to install apps automatically. Most linux distributions based on .deb packages will automatically install maxima on clicking this link. The package manager also provides several graphical front-ends for using maxima. One that aims for completeness is wxMaxima.
In Linux distributions based on RPM packages as an alternative
to the package manager it is possible to enter the Maxima-Linux
subsection and to follow the link to the most recent version. The
page will contain several RPM packages named as:
name-version.i386.rpm, where the first part is the
name of each package and the second part are the numbers that
identify the version. The minimum set of packages that must be
installed are maxima and maxima-exec-clisp.
Since they both depend on each other, they should be installed
with a single rpm command:
rpm -ivh maxima-x.y.z-n.i386.rpm maxima-exec-clisp-x.y.z-n.i386.rpmClisp and Gnuplot should be installed in your system.
You may also want to install maxima-xmaxima, which provides the Xmaxima graphical interface and a graphics program needed by some commands such as plotdf and ploteq.
The maxima-lang packages provide translations of the manual into various languages.
Get the most recent version from the Maxima-MacOS subsection, which will be a single package.
The download instructions and links can be found in the Maxima on Android page.
In systems not included in the previous list or if you want to build a more recent Maxima version or with a different Lisp flavor, get the source code from the Maxima-source subsection. Unpack the file and follow the instructions given in file INSTALL, which can also be read on-line.
The most recent development version of the source code can be downloaded from the GIT repository. That page shows the git command that should be used to obtain a complete copy of the repository. After getting the code, follow the instructions in INSTALL.git.
For Windows a nightly build can be downloaded from Wolfgang Dautermann's Website that also provides detailled results of compilation and testbench runs on many different lisps. For Ubuntu Linux nightly builds of maxima are provided at launchpad.net. There is no guarantee that the sbcl or the gcl flavour of maxima contained in this build will work on other debian-based systems, as well, as it depends on an exact sbcl or gcl version. But the clisp flavour (that is also part of the package and will be used by default) normally does.
If the snappy apps infrastructure is installed (Info on installing it manually is here) the following command installs a distribution-independent, though large nightly build of maxima + wxMaxima on entering the following command:
sudo snap install --edge wxmaxima
Even if there is no guarantee that a nightly build will work the maxima team tries to keep its codebase as stable as possible which means that if something is broken in the nightly build which did work in the release this information normally is important for the developers.