and can you tell me how to get a third party or self-made client modification.

i want the last version for the mac, and i asked and tehy told me in the game that i need to download the subversion and copile with my version, but i dont understand nothing, if you can answer in spanish it will be better

i dont know a lot about his but, i saw a guy dropping items very fast and i asked him, and he told me i must patch my client first, but i have no idea how to do it, and i started asking everybody but they only use windows, so i am lost my qestion is how can i patch my client and what is a client, if...