When we moved from Elluminate to WebEx in 2013, we were not satisfied with the existing Moodle/WebEx integrations, so we decided to make our own.
Our new plugin, mod_webexactivity, is for Moodle 2.6 and above, completely open source, behaves as a proper plugin, and follows all of Moodle's coding styles and best practices.
Instructors schedule meetings simply by adding an activity to their course. In the background, the plugin creates their WebEx user if needed, and configures a meeting. Both instructors and students interact with it complete inside Moodle (except for the meeting itself, of course), with the plugin handling identification and logins seamlessly. Even recordings are accessed from within Moodle.
Learning Management Programmer
I am the lead Moodle developer at Oakland University, a ~22,000 student state university in south-east Michigan. I develop a handful of Moodle plugins, and am a regular contributor to Moodle core.