I would say go ahead. DCS's GUI is great, but sometimes there are certain limitations, such as hovering, live updates without a significant freeze, and just generally a really flexible way for the GUI. (If this isn't true, feel free to correct my mistake.) Besides, it would be a nice, friendly competition as well, right?

I've actually started a DCS Axiom project... that no one has really bothered to help me with.
I'm willing to add people to the project, since it's 100% open source, and I know for a fact that I can't do this all myself.
(My little project is here: http://ourl.ca/10100)
For many things like games and utilities, it's crucial that they don't have too much dependencies. Lugging on 48 KBs as an app isn't too fun, and forces people to compile for DCS, reducing compatibility. People like choice and flexibility, and that something that you and I would like to offer. I'm currently doing the DCS side, obviously.

However, I'd like to join you guys in developing an Axe GUI, although I'm a lame duck until the summer starts. I have some ideas for both widgets, interfacing, organization, and core rendering handling (especially the last one), and I'd love to add them or suggest them to this project.

Keep up the great work!

critor, I've downloaded TNOC and mirrored it.
If you don't mind, I'll eventually also be mirroring all the OSes on TI-Bank as well.

(I maintain a "secret" mirror - that is, it's available for public use, but can't be found on Google. A person would have to PM me to get a link to my little mirror.)

Also, is there maybe an "easy" way to build the RS232 interfacing?

This is probably one of the reasons why we've started to make a calculator (OTZ80) - because we want it done right, both mathematically and freedom-wise! (I've just realized that now after almost a year - no worries, we'll be alive and kickin' again this summer!)

Sparking from this topic (http://ourl.ca/10077/193661;topicseen#new), I've decided to try and see if I can write a DCS axiom! However, my assembly is terrible, so I will need LOTS of help with it. From the messages in the thread, it seems that our assembly devs are puzzled at how to write an Axiom, but could easy make an ASM program. Hopefully, from this topic, a quick start/manual can be written on how to write Axioms. THEN our awesome assembly programmers' powers can be unleashed!

OK, so let's get started!

First off, I'm basing my Axiom from the MemKit template. My assembler is SPASM (part of the WabbitStudio suite), OS Linux.
I also am using http://dcs.cemetech.net/index.php?title=GUI_API for reference on how to use the DCS' GUI libraries in assembly.
With that, I'm currently just trying to write example code for myself (and probably others).
I'm focusing on: http://dcs.cemetech.net/index.php?title=GUI_API#Adding_GUI_Elements

Here's a code snip from the API docs:
ld hl,SmWinData
ld de,SmWinDataEnd-SmWinData
ld a,GUIRSmallWin
call PushGUIStack
ld hl,winButtons
ld de,dat_end-winButtons
ld a,GUIRWinButtons
call pushGUIStack
ld hl,0
call GUIMouse
ret
SmWinData:
     .db 5,5     ;the x and y coordinates relative to the LCD of the top-left of the window
     .db $F8,$88,$88,$88,$F8   ;a square icon
     .db "My Window",0    ;the window title
SmWinDataEnd:
exitMyProg:
  call ResetAppPage
  ret
winButtons:
 .db 00100000b      ;only displaying a close button
 .dw 0              ;null pointer
 .dw 0              ;another null pointer
 .dw exitMyProg     ;we'll jump to exitMyProg when this button is clicked
dat_end:

Of course, we really don't want internal data, but the data for the arguments the user provides!

In the end, after a back and forth on IRC, I've gotten this code:
.nolist
#include "ti83plus.inc"
#include "Axe.inc"
#include "dcs7.inc"
.list

#define B_CALL(xxxx) rst 28h \ .dw xxxx

 .dw AXM_HEADER

 .dw Ax1_End
 .db AXM_ALL
 .dw tok_DrawL ;DlgBox()
 .db AXM_INLINE
 .db AXM_1ARG
 .org 0
 ; OLD CODE:
 ; call OpenGUIStack
 ; ld hl,SmWinData
 ; ld de,SmWinDataEnd-SmWinData
 ; ld a,GUIRSmallWin
 
 ; OK, so let's first get stuff ready! (Open the GUI stack!)
 call OpenGUIStack
 ; Text is stored in HL already, no need to move it around!
 ; Save hl!
 push hl
 ; Now find the length of the string arg!
 call sub_Length
 ; Copy it to the correct place...
 ex de,hl
 ; ...and bring back the string arg!
 pop hl
 ; Set window type!
 ld a,GUIRSmallWin
 
 ; Push the GUI!
 call PushGUIStack
 
 ; Now, add the close button to the window.
 ld hl,winButtons
 ld de,dat_end-winButtons
 ld a,GUIRWinButtons
 call pushGUIStack

 ; Now, render the GUI and give control (mouse) to DCS!
 ld hl,0
 call GUIMouse

 ret

exitMyProg:
  call ResetAppPage
  ret
winButtons:
 .db 00100000b      ;only displaying a close button
 .dw 0              ;null pointer
 .dw 0              ;another null pointer
 .dw exitMyProg     ;we'll jump to exitMyProg when this button is clicked
dat_end:
Ax1_End:

 .dw AXM_END

.end

Unfortunately, this crashes! Is there any errors that should be fixed?

While I was poking around in the interwebs, I found this little gem:
http://www.wabasoft.com/download.shtml
Look for "SH3" - if you modify it a bit, you can probably get a mini java on the Prizm!

EDIT:
It also appears that it's FOSS, and so the source is here: http://www.wabasoft.com/download4.shtml
It's now much easier, although you still have source to modify, as this is still for Windows CE.
This should definitely be interesting

Basically, the debug interface has finally been unlocked, and now what used to be only seen in the emulator is now seen directly from the hardware! Flashing refers to rewriting the whole OS (and potentially the BOOT2), allowing us to use the *entire* hardware!

(I might be wrong - please correct me if that is the case.)

I've been working on such a thing too for C2I...
Maybe we can combine our efforts and make it a reality?

Coming on for just a bit - I've modified those rules (from yunhua), as they look a bit unclear to me.
I've also fixed any spelling or grammar mistakes:

1: Rude, unconstructive comments towards a project used in attempt to discourage the author is not allowed.  Criticism should be intended to make the person's program better than its current form. Complaints about people, respect, etc. should be resolved via PM, not in the public. Complaints anywhere else is not allowed.

2: Don't double post unless there has been 6 hours since your last post, 3 hours if your thread is not on the New Posts page (remove?), or 1 hour if it's a project update. You can also double post immediately to upload more than 10 attachments at once. Otherwise, update the last post using the "EDIT" or "QUICK EDIT" button.

3: No duplicate accounts - they will be deleted. Evading an ignore list (private messenger) will lead to a permanent ban without warning.

4: Vandalism, porn, warez, ROMs, copyrighted music and any kind of piracy are not allowed.

5: Advertising is not allowed unless it's a calculator project (or, in some cases, selling/requesting a calculator). However, if you are buying/selling a calculator, and a transaction fails, Omnimaga claims no responsibility. For calculator projects, create your own topic for your own project. Do NOT use others, unless its a mini-project showcasing thread.

6: Flooding and spam outside the "Randomness" section (invisible to guests) of the forums, using the character "•" (not sure what this is... could we replace with "using obscure characters like "•" without reason"?), or posting everyone's nicknames on IRC for no reason is not allowed.

7: Not suitable for work/children (NSFW/NSFC) content outside the "Randomness" section of the forums is not allowed. This excludes swearing, which is allowed everywhere, providing it doesn't break rule #6.

8: Unauthorized bots on IRC with any public commands that can output public messages or unrequested private messages are not allowed. Bots that are silent, authorized by an admin, or that just logs are allowed.

Hope this helps!