I like that it's open source, free to use/download as well! It works really great with my other software (Sage).
The interface can be confusing at first but after some time you learn how everything fits together perfectly - very helpful when working in tandem systems such mathworks or sage!! A perfect program if your looking into either of these two programs already :) Math problems are solved quickly using this product which saves me tons upon hours spent doing trial-and error calculations manually instead.