TABULA - a scientific calculator for the 21-cent
Vector, vol 20 no 4, p62. 
First Steps ...
To install TABULA and begin to use it, read: the Getting Started guide.
If you are not a J user and you want to run TABULA, then here's how to install TABULA from scratch.
... And Beyond!
Now work through ChurchClock which builds a ttable from scratch and exhibits TABULA's main features.
See LaunchElephant for another worked example. Emphasises building the example and does not go deeply into how TABULA works or what the buttons do. So it is best to go through this one after ChurchClock.
Contributed by Ian Clark