latex and word,

["vsgdp"]

Hi, so how do people write math documents?  I've used a latex type notation 
on a math forum in which the forum would automatically convert it to math 
symbols dynamically.  Is there a plugin for MS Word in which it will convert 
the latex code to a math symbol image?  Do people write their math works in 
MS Word?  Do they use a separate program to generate images for the math 
equations and then import these images into MS Word?

Thanks for info.