So earlier today I was messing around with my fellow calculator nerd and I borrowed permanently all 4 of his calculators. The thing is, he never came to me to get them back, he knew I had them, but he just kinda left. So lucky me! I now have 5 (including mine) calculators!
A TI 84 Plus, TI 89 ti, TI 84 Plus CE (mine), Nspire CX CAS, Casio classpad fx-500.

Now I can't just do nothing with them, I'll probably never have this chance again.

So my question is: what should I install on them? (that is of course harmless)

Well, what you could do other than install stuff, is learn platform-specific programming (for example, CE-only commands vs. 84+ text graphics), work on making games cross-compatible, learning new languages (Lua and C on the Nspire, C on the CE), and other fun stuff like that! You could probably also reliably test multiplayer games on the 84+ and CE.

C on the nspire requires ndless which I am not sure your fellow calculator nerd would accept being installed (you would have to ask him before doing it)

I'm pretty sure TLM's "nerd" gave these to him, and doesn't expect them back, so, he can.

Wat, of course he (probably) want's them back! And yes, I wont be installing Ndless without his permission.

I'm confused. You permanently borrowed it, and he didn't come to you to ask for them, but you want to ask for his permission to install ndless? So like you get it, but can't do anything bad to it?

Why wouldn't he? They are like crazy expensive. Get his permission

Well, you could send them all to me... just saying, I have always wanted a ti nspire...

You could take them apart, look at the differences, and see how they work! Hands-on electronics class (probably not a thing but oh well)

Get maze 2 for the CE and maze 3 when it comes out

I see you advertising! For all of the calcs? Only one can run it. TLM is trying to use ALL of them. You forgot a period. I die. And then get up and run away.

Trash all the calculators except for the 89T and learn C for the 89T

get TempCheck CE ICE, and all of my CE progs

But really, NSpire BASIC is just meh to me, the 84's are what I like to program. Of course if I had a NSpire, I'd use it for primarily gaming, and I've never had a Casio Classpad or a 89T before, so those are up to you!!!

Why are you recommending programs for the only calculator I own...
***TLM runs

I love that idea jcgter, however I don't want to risk messing something up.

Anyways, yes I had a lot of fun messing around with these calculators, I found out that the Casio is great for complex problems, but is slower with simpler problems, go figure. The TI lineup is much faster at simpler operations.

I didn't install anything on the Nspire nor the Casio, however I put fruit ninja on the 84 Plus and jumpman on the 89 ti.

I'm going to convince him tomorrow to put in his will "All my calculators go to TLM".

That's the only calc I own

Well, I know exactly what you might want to do with the TI-84+

For the 84+, I think you should go wild with DoorsCS, calcnet, Trusound, etc. With the nspire, do ndless and get things like gbc4nspire, Linux, Crafti, etc.
Installing ndless won't do anything bad/irreversible to your calc, so you really shouldn't be wary of it.
The fx-cg500 is too new and too uncommon to have any noteworthy projects going for it. The 89 you should use for actual math, and learning ti-89 basic, because it is quite interesting.
And of course, the CE is great for ICE, and C, but you already know this

gbc4nspire does not work on hw rev W+ (I have an AB) but gpSP works fine

I was obviously talking about the replacement mainboard
But I would rather do that to a used or dead one.

Thanks womp for those ideas! He already has Doors installed next time I get his calc though I'll install the rest of those programs!

timedia: I believe he has a compatible model, thanks for informing me though.

Muessigb: Honestly, that project is so awesome, I don't think he'd mind once he finds out that it's running freaking Linux.