How do i install newly downloaded programs?

How do i install new programs I see in the forums?

For the most part you can just download them and run them. You will need to make sure the program is available to the computer you are trying to run them off of. Anything that has special installation requirement should have them noted in its post.

Computer root directories are located in %APPDATA&/.minecraft/saves/worldname/computer/computerid for ssp and
mincraftserverfolder/world/computer/computerid for SMP

Or you can place them in the /rom folder to make them read only, from your .minecraft or minecraft server folder goto
/mods/ComputerCraft/lua/rom

If it's read only, what difference does it make in the game? Does that mean it's run only?

It means that others players will not be able to edit the program from within the game. They will either need access to either your computers file system or the minecraft servers file system in order to edit the program.

Thank you so much! I just have one final question: If by putting it in the rom folder, will it be under the programs menu when in the in-game computer?

It you place it in /rom/programs I believe it will show up, not 100% sure, I would check to see but I'm not to where I have access to MC or CC right now.

How would I install it if on SMP if i was just a user? Without access to the servers files.

If http is enabled you could probably use the Pastebin to do it. I have not played with that as I have no need so I would have to play with it some to give you an example of how to do it.

Otherwise you will have to manually enter the code using Edit, or get a server admin with file access to do it for you.