Altair is a program analysis tool for exploring system modularity. It analyzes how APIs are implemented, computes pair-wise overlap, and clusters them into modules. It can be used for API documentation, recommendation, specification mining, among others. Altair was developed as a 6.867 (Fall 2008) class project.
The ESEC-FSE 2009 paper "API Hyperlinking via Structural Overlap" explains the basic idea, including the measures and the algorithms.
The demo API references are produced by Altair and powered by Exhibit.
Note that you may see nothing using the evil browser.
Altair runs on FreeBSD, Linux, Mac OS X, and Windows. It should also work on other UNIX-like systems.
Altair accepts bitcode as input, which can be generated from source code using LLVM GCC or Clang. The prebuilt test package (including bzip2 and httpd bitcodes) is provided for convenience.
Altair is distributed under the MIT license.