Creating a programming language?

Does anyone know how to nessiclarily make a programming language? Like PHP and HTML?

Well.. First I have to state that I've never actually created a programming language.. but here's a few things you need to decide before you start

1) Will it be a compiled or interpreted language? Examples of compiled languages: C, C++, Java, Delphi, Visual Basic, etc.. Examples of interpreted languages: PHP, Python, Perl, etc..

2) Define the language syntax.. i think this one is self explanatory.. oh, and you should decide if you want it to be fully OOP (Java, Python), fully procedural (C), or a mix of both (C++, PHP, Python)

3) What language are you going to use for the compiler/interpreter? The more low-level you go, the faster it will be (ie. a compiler written in assembly is probably going to be faster than a compiler written in C.. however, that also depends on your skills)

4) You also have to decide things like how the language will handle hardware, memory, etc... How the language will use the file system... and also what kind of built-in functions the language should have

As you see, there's lots of stuff you have to plan before starting to write the compiler/interpreter..