Nothing beats free.  The tools I list here are hard to beat in terms of price, and even if your customer insists on a certain name brand tool suite, these may come in handy for prototyping the development before you spend the time and money to use another method.

Perl:  ActivePerl Community Edition by ActiveState: 
http://www.activestate.com/activeperl/downloads

Free MATLAB knockoff:  GNU Octave:
https://www.gnu.org/software/octave/

Image editing:

GIMP editor – poor man’s Photoshop:  http://www.gimp.org/

BASIC:

JustBASIC:  http://www.justbasic.com/

Don’t forget that if you have Excel installed, you can use Excel VBA when you create a .xlsm file. All the functionality of Visual Basic coupled with the responsiveness of a spreadsheet.

RFO BASIC for Android is also good: http://laughton.com/basic/