Total Commander - A Shareware file manager for Windows® 95/98/ME/NT/2000/XP/Vista/7, and Windows® 3.1.
Elyse - The free version allows up to 30 tags.
Double Commander - Double Commander is a cross-platform open source file manager with two panels side by side.
DEVONthink - DEVONtechnologies develops DEVONthink, DEVONagent, and other Mac and iOS apps for document and information management and web research.
XYplorer - File Manager for Windows
Leap - With Leap you find things based on your natural memory of that file.