Hello everybody!
I'd like to present you my new creation - GBXedit.

It's has NO GUI (Since I don't like playing with Swing), everything is commandline based.
Required JRE 1.7!
Everything is explained in readme file inside the archive, short info on how to blockmix is there too.

INFO (Read before ask):

• THIS WAS TESTED WITH TM2 STADIUM. SHOULD WORK WITH CANYON, BUT I CAN'T CONFIRM THIS.
  
• If someone want's the source, PM me. Program is written in Java.
  
• If someone want's a GUI - write it then. I can give you the source. The track operations are separated from user input/commands execution, so porting to GUI wouldn't be so hard.
  
• This is not full working editor. Just alpha test. It's somehow heuristic (due to byte searching functions), but It's really hard to crash it this way. It should work on 95% of maps
  
• If you want to edit something more - just dump the uncompressed data (there is a command for it), and use HEX editor. You can load the dump back with another command.
  
• If I find some more time I deafinitely gonna add Daytime changing (Blah, it's stored the worst way Nadeo could do that), and other strings editing.
  
• Some other questions are explained in FAQ section of readme.
  

DOWNLOAD: (sorry for adf.ly, but I think my work is worth those few cents)
Version 1.2 (Reduced crash ammount)
Version 1.1 (Display bugfix)
Version 1.0

I saw this on MP Forums as well. Thanks for cross-posting it here. It's an interesting tool. I look forward to see how it progresses.

We are currently reworking the core and implementing a GUI

Shadow96pl says:

It's has NO GUI (Since I don't like playing with Swing), everything is commandline based.
Required JRE 1.7!

God, Java? No wonder you didn't make a GUI at first xD

where can i downloud?
your link is falsh