https://github.com/lionleaf/dwitter/wiki
some write-ups:
http://jsriffs.blogspot.com/
http://zozuar.org/txt/chalice/
http://zozuar.org/txt/sc/
Check tutorials for 64 KB, 4 KB and such.
Think of 140 characters as trying to do 140 byte executables.
The basic idea is to first create whatever you want to achieve, without thinking too much about the size.
Then you iterate the algorithm, reducing the size until it achieves the desired goal.
In the process it helps to make use of typical demoscene technics, namely packers/minifiers, procedural generation.
