I have a phone line, I'm a beginner with VoIP and I'm a software developer. I want to plug my home phone line in my modem and start some VoIP activities such as receiving call from my Computer, auto answer messages, call redirection and execute custom script depending how the user would intereact with a certain menu (get input numbers and give a different options / message or execute a custom PHP script). I want to have some flexibility and to be able to program some more features.
I think the best solution would be to start with an existing free Open Source solution for my needs (preferably PHP, Java or Perl).
Do I need to purchase a certain "hardware" or something else or it could be free from A to Z using an open source solution ?
What would you recommend me ? Where can I start ?