TV guide listing API [closed]
The MythTV folks have gathered resources for various countries here. If you're in the US or Canada, they recommend the Schedule Direct service.
These services are generally based on the XMLTV data format/toolset.
Rovi offers both SOAP and REST APIs for TV listings. It supplies listings for all channels of the cable, satellite, and broadcast services in multiple countries. Rovi is the source the cable companies use. See this website.
Schedule Direct doesn't grant commercial licenses. I'm checking out tvrage as mentioned above and Rovi right now.
Edit: If this is a commercial project, I recommend contacting Tribune Media Services (click "License our Content" in the footer at Zap2It.com). That was the solution I chose for my company, simply because they were much more prompt in their response than Rovi. The paid listings are XML files.
If all you need is a non-commercial license, SchedulesDirect works very well. If you have questions about their licensing, they encourage you to ask. We started using their listings and then had to change tack because of licensing issues.
You could contact staff of WebTelevideo at [email protected] that has solved your problem. They may provide you an account to their own API.
WebTelevideo API has TV Scheduling for many countries and metadata (actors, directors, plot, trailers, posters etc..)