TextWorx lets you access a large suite of text manipulation functions within any text editor or browser. It provides a universal context menu and custom toolbar/s that you invoke with a hotkey. To use, select the text that you wish to manipulate, then open the context menu and select the function that you wish to run the selected text against.

The things you can do includes: insert various date formats, change case to various different formats, delete duplicate lines, HTML tags, multiple regex search-and-replace etc. Note that you can easily add your own functions by editing a INI file, so it can be fully customized to your own needs.