- Syncasaurus – xplatform Perl-based bookmark synchronizer
- moz2web-tools – Mozilla To Web Bookmark Tools
- bk_edit v0.6-5 – bookmark editor – gtk based bookmark editor; actively developed, german
- XBEL – The XML Bookmark Exchange Language
- Netscape Bookmark File Format – documentation at MSDN of all places
- nsBookmarksService.cpp – hmm, it’s only 5700 loc to dig through…
- Linux Links: Bookmark Manager
- HotScripts: PHP Bookmark Management, Perl Bookmark Management
- Web-Based Bookmark Managers
Look into: Bookmarker, Bookmark4U, Active PHP Bookmarks, ol’bookmarks, LinkBase, b., XBELette, PBM, bookmarksync