.M4 File Extension Information

What program uses .M4 file extension?

Program : Meta4 Source Code
Program Website: Meta4 Source Code
Company : Meta4
Company Website: Meta4

Extensions starting with

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | #-0-9