If your goal is to study or develop mods for a you own/operate legally, please:

If you are downloading these tools from forums (like elitepvpers or RaGEZONE), be cautious. Many "modded" extractors come bundled with malware. Always scan the files and try to find the original releases by respected developers (like Drew Benton).

Here are the key features and details regarding PK2 Extractors used in the vSRO scene: