There was a download of VCC 2.3 on the developer's website when we last checked. We cannot confirm if there is a free download of this software available.
According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. The actual developer of the free program is Microsoft Research. VCC lies within Development Tools, more precisely IDE. VCC.exe or VccPortCasa.exe are the common file names to indicate the VCC installer. The most popular versions of the VCC are 2.3 and 1.0.
From the developer:
VCC is a mechanical verifier for concurrent C programs. VCC takes a C program, annotated with function specifications, data invariants, loop invariants, and ghost code, and tries to prove these annotations correct. If it succeeds, VCC promises that your program actually meets its specifications.
You may want to check out more software, such as Microsoft Research Vcc, Velocitek Control Center or Virtual Chess Clock, which might be related to VCC.