TeX4PPT and TeXpoint. It's much more professional but it is not for free except for a one-month trial.
If you prefer knit clothing over latex, there are five relevant blogs:
The Physics of Fireworks (Synopsis) - “Celebrate the independence of your nation by blowing up a small part of it.” -The Simpsons When gunpowder was first invented more than 1,000 years ago by ...
10 hours ago