These programs are being forgotten by time, but I conserve them.
The legendary Thai word processor running on MS-DOS for someone who wants to recall your old days. This software do not run on Windows Vista and ever so you may need DOSBox emulation.
Another legendary Thai word processor that I found. It runs on MS-DOS and you may need DOSBox too. I used to use this for studying in class.
This version of QBasic is the most popular.
This version of QBasic has much improvement but it might simply waste.