As per #1 all files are dual-licensed with
- GNU Public License, version 2.
- LaTeX Project Public License, version 1.3c.
Missing libraries are deprecated and can be replaced by the tikz-ext package.
See its own repository.
See the wiki for a description of the libraries.
There are two ways to install these custom libraries for use with one's own documents:
- Placing them besides the document's main TeX file
- Placing them in the local texmf tree