SmartXPlore is an add-ons system for Windows Explorer. Each add-on is available using the middle mouse click in the Explorer Window. Same actions refer to selected files, other to the current browsing directory.
From the blog
How often do you use Windows Explorer to browse your files? What if you can download add-ons for Windows Explorer in order to easily share files, manage them, tag them and …
SmartXplore will let you do this and more: think you can have lots of new options to manipulate your files just one click from you.
SmartXplore is free and open source.
Note: The first beta version has many features, but probably some bugs. Please send feedback.