Heya and welcome to the forums!

Unfortunately, as far as HP Prime hacking goes, it's pretty much dead. Nobody will ever hack the HP Prime because nobody seems interested in doing it for a platform that has less than a million users in the world

Even TI-Nspire hacking is dead, although there are a few games still coming out every now and then. No more Ndless development nor anything else, and that's with a much more popular (although more closed) platform. It took three years until ASM arrives on the Nspire too. Same for the Casio PRIZM, but again, hacking it is no longer as needed, since Casio has done nothing to block third-party ASM/C code.

For the next few years, we'll have to stick to HP PPL language (although that's already quite fast enough for the time being, since it's compiled).

On a better note, apparently it was discovered not so long ago that the HP Prime pretty much lacks any viable protection against third-party OSes. In other words, someone could disassemble the HP Prime OS then modify it to add a LaunchASM() command that runs ARM assembly or C programs. He could even write his own OS or make such mod avaialble as IPS patch to avoid getting in trouble by releasing an OS containing copyrighted content.

Besides that, if you or anyone else knows enough ARM assembly, hacking and stuff, they are well welcome to help finding other alternatives. Of course, keep in mind that in the future, HP might release OS updates that could unintentionally (or if they're like TI, intentionally) block ASM exploits.

Hey thank you. If I have thought I would start such a discussion with a 'hello' ^^'

Well I bought the Prime because I was a huge fan of my two 48 that I used to program in asm (I loved Saturn asm, Jazz was so cool). But I lost them some years ago when a fire started in my flat. I don't have the real machine yet (should be here in the next few days), but I played a while with the simulator. At first, I must say I was a little disappointed. A lot of cool feature of the 48 are gone, RPN is not half as practical as it was, and RPL miss me a lot. The filesystem (sort of) that used to manage objects and variables too. It was just excellent.
Of course when I saw the specs, I wanted to program it in some low level language... I sure can help and contribute to some sort of hacking, but I'm not a reverse-engineering guru of any kind, I know nothing about ARM asm (yet ?), and I have a job that can take me lot of time, so I won't start any project myself.
But you're right, PPL seems quite fast, and it should be fun to try and do amazing things with it.