Testos (Test Tool Set) platform focuses on support of automated testing of software. Tools within the platform combine different levels of testing (from unit to acceptance testing) with different categories of testing, such as model-based testing, requirement-based testing, GUI testing, data-based testing, and execution-based testing based on dynamic analysis. All contributions to the platform are developed using state-of-the-art techniques and exploit current research on software testing and run-time analysis. The platform connects all its components in such a way that it can deal with wide range of problems from usability analysis of SUT frontend to automated generation of tests conforming to higher SIL-level applications requirements of IEC 61508 standard (e.g. MCDC coverage).