Not sure what it is, but it's definitely not the FN P90. The FN P90 has the magazine on top of, and in line with the barrel of the gun, and downward ejection. Is it the HK PDW?
It's definitely not a Bofors Saab PDW. The Bofors superficially resembles an Uzi with a sliding wire stock with a forward vertical handgrip that doubles as a spare mag carrier.
My guess would be an aftermarket bullpup kit for one of the common "assault weapons".
The picture on my end looked bad, because the video on this computer isn't what I have at home, but I think its one of the muzzelite bullpup kits. The magazine looks like 223 ish. I am going with PreserveFreedom's assesment. Ruger Mini-14 in a bullpup type stock
This bullpup dosn't exist. It's a computer generated image from a Japanese animation. It's supposed to be a 5.56 bullpup with a carbine length barrel inspired by the P90. Looks pretty convincing though doesn't it?
The top one looks like an AR-15 in a bullpup-stock (two-part receiver, definite AR mag), but the bottom one looks like one of the tricked-out M1 Carbines they used on "Planet of the Apes". How close am I?