What is TeXlipse?
TeXlipse is a plugin that adds Latex support to the Eclipse IDE. It supports Syntax highlighting, Document outline, Code folding, Templates, Build support, also partial building, Annotations for errors (while editing), Content assist (completion of commands and references), Easy navigation with F3, Outline of the current file and the full project, Spell checking, Menu with common LaTeX math symbols, BibTeX editor and BibTeX-support, Line wrapping, Table editor Support for several platforms (Windows, Linux, OS X), ...and many more
The project seems to be abandoned. Last version, 1.5.0, released on November 2011, can be still downloaded from SourceForge.