From the project's website: "Emacs-IDE is an Integrated Development Environment (IDE) interface for Emacs (code browsing, compilation, debug...)."

[https://web.archive.org/web/20170506205806/http://emacs-ide.tuxfamily.org/ Wayback Machine link].

[new]
How is this related to ECB (EmacsCodeBrowser)?

I don't think they are related.  Maybe Emacs-IDE uses ECB, I don't know.  However, the former is designed to be run in a stand-alone Emacs instance, not as a package like the latter is.

----
CategoryModes CategoryProgrammerUtils CategoryProject