What are the major producers of Flash and RAM based FPGAs?

hello...
I'm new here, so sorry if this doesn't belong here
I'm writing an essay about FPGAs, and I couldn't find anywhere some list with major FPGA producers and device prices... hope u can help me...
and something more, can somebody explain me major difference between FLASH and RAM based FPGA? have some generall ideas, but it's a little bit confusing now...
thanx

FPGA producers

Try to get your hands on the book "Programmable Logic Handbook : Plds, Cplds, and Fpgas" by Ashok K. Sharma. It has a lot of good material. I can't find a copy online though. The best bet for online info is manufacturer's websites. Some companies that manufacture FPGAs:
Xilinx
Atera
Atmel
Lattice
Fujitsu
Actel
Cypress
There are others. If I think of more, I'll post.

FPGA producers

Here's some general FPGA info, including the names of the major manufacturers:
https://en.wikipedia.org/wiki/Fpga

For device prices, you will need to dig a little. Visit the FPGA manufacturer web site to find device part numbers (you may need to download FPGA data sheets to find specific part numbers), then check their web site again to see which distributors sell their parts, and then visit the distributor web site to check price and availability. Here are three major parts distributors in USA, there are many smaller ones:
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RAM-based is the most common: After you power-up the FPGA, you must download your logic configuration into the FPGA's internal RAM.

Flash-based: You burn your logic configuration into the FPGA's internal flash memory. Then it's ready to go the next time you power-up the FPGA.

Re: FPGA producers

thak u so much, u've been a great help