There used to be two versions of GPLFlash: GPLFlash and GPLFlash2.
GPLFlash2 is now depracated and not maintained anymore, all developpers ditched it in favour of gnash. It's still accesible here for informationnal purpose, we will not provide support or help of any sort as will only decided to pursue the GPLFlash (v1) effort.
The latest GPLFlash release can be downloaded from here. The latest release is 0.5.4.
Since GPLFlash2 was still in development when it stopped, it is only available via CVS.