libwsclient
WebSocket client library for C
This library abstracts away WebSocket protocol framing for client connections. It aims to provide a somewhat similar API to the implementation in your browser. You create a new client context and create callbacks to be triggered when certain events occur (onopen, onmessage, onclose, onerror).
Your best bet for getting started is to look at test.c which shows how to connect to an echo server using libwsclient calls.
Also, to install:
./autogen.sh
./configure && make && sudo make install
Then link your C program against wsclient: 'gcc -g -O2 -o test test.c -lwsclient'