Dunno if anyone already knows it (search gives no matches), btw it seems very interesting:

Explorer++ is a free multi-tab file manager for Windows (C++ / GPL v3).

Available on Windows XP and above, it features the same familiar interface as Windows Explorer, while introducing several enhancements and improvements for a much richer file browsing experience.

Features:

• With the option to save to the registry or a configuration file, Explorer++ is completely portable.
  
• Tabbed browsing for easy management of multiple folders.
  
• Display window shows previews of files as they are selected.
  
• Easy-to-remember keyboard shortcuts for quick navigation.
  
• Customizable user interface.
  
• Full drag-and-drop support with other applications, including Windows Explorer.
  
• Advanced file operations such as merging and splitting supported.

Official website

SF.net's project page

Hope that inspires !

Edited July 7, 201016 yr by patchworks

I installed it on my WinXP machine and like it. Unfortunately it doesn't run on Win98SE even with KernelEx 4.5 RC1 (missing shell32.dll export).