CSound

CSound is essentially a computer programming language for synthesizing sound and music. Constructed using the C programming language, CSound is an open source program that is available for download on PC, Mac, and Linux operating systems. The software allows for modification and adding onto through C code, which, through users throughout its lifetime have done, have expanded the range of its abilities and given it the large sonic palette it has. CSound is also paradoxically both simple and complex to work with. All you really need to write music in CSound is a text editor two write the two text files orchestra and score and allows the user to work within a completely modular system without GUI limitations constraining user intent. However, since that means there is no real custom work environment for CSound, there is a much steeper learning curve to the program, as there's nothing pre-made to tinker with.