I heard alot of people trying to find out how to use the site from makinit(http://cjobjects.makinit.nl/) so i will tell you the toturial.

1. Go to this site: http://cjobjects.makinit.nl/
2. Go to map editor on transformice
3. Now don't make a large map or whatever. First put a ground like wood ground, grass,..
4. Now go back to cjobjects(the site) and choose a object then click on it.
5. Go back to map editor and make a small thing that is the same lenght or height like the object from the site.
6. On map editor click on Save/Load/Test and click: Copy map to clipboard.
7. Go back to the site(from cjobjects) and paste it on: Input/output XML
8. Click on generate object.
9. Now go back to transformice and select the ground that was the same lenght and height like the object.
10. Look at how L : and H : is and which color it is.
11. Now go back to cjobjects site and find where the L :, H : and color is.
12. If you find where it is then you will see o = "(color code)"
13. If you see that, remove only the o = "(color code)" and nothing else.
14. Now copy the whole thing and paste it on map editor on code.
15(If you want to make the object dynamic). Click on the ground from the object and click on dynamic ground.
16. Now you can test the map! If it did'nt work to you, I'm really sorry, just tell it to me so i will explain you better!

A thread about cjobjects already exists here, you can use it to talk about this helpful feature ^^