Fortify
Application security testing: static analysis, dynamic testing and SCA
Frama-C
Platform for analysis and formal verification of C source code
Gendarme
Rule-based static analysis tool for .NET and Mono assemblies
ht://Check
Link checker and web accessibility checker
HTML Tidy
Console tool and library that corrects and cleans up HTML and XML
HTML5test
Online test of browser support for HTML5 features