Ada is a really good system programming language, especially if you have to get very low level, where the language allows for very fine control over memory layout and for interfacing with hardware. All that _without_ sacrificing type safety. In addition, if you want to make your software even more bullet proof, you should consider the SPARK subset of Ada and statically prove the Absence of Runtime Errors, which includes memory safety. Furthermore, with SPARK you can prove various higher level properties of your software, thus reducing the number of unit tests needed.