Anaconda provides more than Python libraries (C/C++ libraries, R packages).
The conda package manager can create isolated 'environments' (like virtualenv but not only for Python) that are very space efficient due to using hardlinks.
The conda-forge community has sprung up to develop recipes and provide packages. The Anaconda Distribution recipes are now actually built from github forks of these conda-forge recipes (we hope to achieve binary compatibility with them sometime soon).