Given the right conditions, many egg layers lay eggs. They are unlikely to survive to hatch in a well-stocked tank, however, due to predation.
I find the best way to ensure that some survive is to either put the adults into a spawning tank with large rocks or marbles on the floor of the tank, or use a 'false bottom' made out of plastic canvas sheets, so that some of the eggs can get out of the reach of the adults.
Hatched fry are smaller than livebearer fry for the most part. The next challenge is getting live foods small enough for the fry to eat. Greenwater and infusoria both work well as first foods.