LilyPondTool provides a plugin for jEdit with a lot of features that can help making LilyPond scores faster, easier and with less error. Features include:
Document Wizard to set up documents easier with lyrics support
Integrated dockable PDF viewer with point-and-click support
Structure browser with code folding
LilyPond parser for finding simple errors during typing
Convenient running of LilyPond and related tools
Automatic code completion for typing commands and tweaking properties
Automatic hyphenation of lyrics using OpenOffice dictionaries