Linux [MAYBE SOLVED]• How can I use .SO files ?

Actually there are a few questions that I want to ask.
EDIT : I got the answer to the first two questions in another forum. I just need help with the third question.
1• I don't know much about Linux. .so files on Linux = .dll files on Windows, is it correct ? I mean, does both types of files perform the same function?
2• Can I write .so files in any language? (for example: C, Java, Python etc. especially C++) or .so files can only be written in certain language?

3• Can I use .so files in Game Maker like .dll files? Can I use the "external_..." commands like external_call on .so files in the same way as this tutorial? I mean, is there a different way for .so files, or just use the same methods ?
Tutorial :

Thanks in advance :) ♥♥
Last edited:
I know that .so files is for linux. I'm just wondering if the logic of the .so files is exactly the same as that of the .dll files. The manual says .so files are equivalent to .dll files. I think this means that I can use both files in exactly the same way in GameMaker ? I guess that's right. Thanks very much dude. :) ♥