games.softpedia.com - Slitherlink downloadable game. This generates puzzle at various levels and dimensions. Also you can upload a puzzle (external to the site) to solve it.
krazydad.com - A large number of printable PDF books of slitherlink puzzles of various levels available to download or play online.
- A suggested notational system to document slitherlink puzzles.
Loopy - One of the many simple desktop puzzle games for Windows/Unix by Simon Tatham.
