There is something magic in the mind when you work until late, it seems that the lack of distractions really help, but if your body is not prepared, the next day you loose al the time that you have saved triying just to be wake up.
Our base language is PHP, but since we are working with teaching programming we are working with a lot more Javascript, Actionscript,C/C++, Java, and lately we have been testing/working with haxe.
I think it is possible but is really hard, even if you are a dad.
2 years ago i started my startup here in Chile, but in that time things didn't work and i had to return to a regular job, i married and had a beautiful little girl 2 days after the Big earthquake here in Talcahuano.
This lasts months i have been constantly trying to go back with my "old" startup, but is difficult.
A lot of time i struggle with the ideas give to my family a better future or a better present, because as long as my experience says you have to take a lot of family time in order to success in your dreams and projects, specially when you are in a "regular" job.
Thanks god, now with the help of my wife we are getting back to work.