Vanilla MakeHuman downloads
If you want to download the source code for MakeHuman and/or run from a source snapshot, see the MakeHuman BitBucket repository.
If you want all the commonly used plugins (such as the asset downloader and MHX2), you can download them all in one zip. Unzip this in the plugins directory where you installed MakeHuman.
For blender there is another zip containing the relevant blender plugins (maketarget, makeclothes, makewalk and MHX2).
Otherwise, you can find MHX2 on Thomas Larsson's MHX2 BitBucket page (For this you will most likely also want to read the blog/docs found at https://thomasmakehuman.wordpress.com/ but slowly being migrated to http://diffeomorphic.blogspot.se/). The other extensions, such as the asset-downloader plug-in and the sync-mesh tool, can be found at our community-plugin repository.
Extra assets such as clothes, hair and skins
More assets for MakeHuman can be found in the online repository.
You can found old stable releases at http://files.jwp.se/archive/
Related & useful
These tools are not part of MakeHuman, nor managed by MakeHuman, but are often used in the same pipeline.
Blender is an open source 3d modeler, ray tracer and a whole lot else. This is the 3d software/environment that will work best together with MakeHuman
MeshLab is a tool oriented towards processing large meshes and provides a set of tools for editing, cleaning, and converting meshes. This is useful for producing all-quad meshes for example.