Appears that memory compression is in these days. So, to be in, here is another method. This one is called "Native API Compression".
Apparently it's LZ1(LZ77) compression algorithm or something very similar and it's available through one or two dll calls. Of course that files can be compressed too by this method.
Functions with small example:
$sString = "lzwlzwlzwlzwlzwlzwlzwlzwlzwlzwlzwlzw"
ConsoleWrite("Before compression: " & Binary($sString) & @CRLF)
$BC = _LZNTCom