Frink beats everything including Maxima when it comes to unit conversion and dealing with mixed-unit calcs. You can do money exchange calculations like: 54 U

Frink beats everything including Maxima when it comes to unit conversion and dealing with mixed-unit calcs. You can do money exchange calculations like: 54 USD - 25 SAR, and Frink will spit out 47.33 dollar (currency) I use the graphic example program and customize it to print out graph paper. You can set the graphics to print at true measurement! Animations, input forms, graphics, all with mixed-unit calcs. You program in Frink's lang, which is a simplified Java. Reminds me of Groovy. I just like the fact it is a desktop IDE with choices on programming or simply converting units. The examples you can download off the main page are amazing and fun. The documentation is great too. I have been using Frink for a long time now, so I just made a donation to Alan who created and maintains the project. It has saved many a headache and error with carrying different units, and I've had fun with it. It's like a cool little programming environment. EDIT: It also runs on Android, and there is a GCJ compiled exe version for Windows (experimental).