allTags was developed to manage large file sets efficiently. Time-consuming actions, like naming files and choosing folders, are replaced by fast tagging operations.
With built-in support functions, allTags avoids inconsistencies and speeds up file description and retrieval. allTags is 100% free to use.
TMSU - TMSU is a tool for tagging your files.
TagSpaces - TagSpaces is an open source platform for personal data management. With TagSpaces you can manage and organize the files on your laptop, tablet or smart phone.
Hydrus - A personal booru-style media tagger that can import files and tags from your hard drive and popular...
File Name Tag Explorer - File Name Tag Explorer lets you: Organize your files with tags.
Tabbles - Tabbles use tags to organize and find files along with your colleagues.
Danbooru - Danbooru is an advanced, tag-based image board system that is based on Ruby On Rails.