you can download from Romulation.com
Games-engine or hkorz
i don't know want your taking about but if you mean R4 card i know a R4 card is a DS card that you can download games for free
if you have a ds simply buy a r4 and search the internet on where to download the games
you can go some website to download free ds games. there are many online store offer free ds game download. After download the games, unzip the patch, drag and drop the games into the root directory of the MicroSD card. then they can work on your r4 card.
You can download the game file over the internet but you also have to download the sav. file
If you connect to the DSi Shop, you can filter by price for free software.
many websites but the one i use is romulation.net hope i helped :)
Yes, that is what the R4 is made to do.
You download the R4 menu off the website, what do you think?
homebrew
no
you can't its illegal!