You're free to use any language that you feel comfortable with as each question is looking for a single numeric answer that you enter manually. Each question is designed to be solvable within a minute with a solid implementation of mathematical algorithms and good use of programming trick. After you solve a problem, either by brute forcing the answer or utilizing your own devised algorithms, you will have access to a message board about that problem, giving you tips and tricks to make your program better which you can use for later problems.
What is Project Euler?Project Euler is a series of challenging mathematical/computer programming problems that will require more than just mathematical insights to solve. Although mathematics will help you arrive at elegant and efficient methods, the use of a computer and programming skills will be required to solve most problems.
The motivation for starting Project Euler, and its continuation, is to provide a platform for the inquiring mind to delve into unfamiliar areas and learn new concepts in a fun and recreational context.
So go ahead, create an account and start hacking away with your favorite language. One by one, you'll solve the 330 problems and get on a roll. Hell, you might even learn a thing or two.