Apple Push Notification Service Gateways

I’ve not yet had the request to implement Push in an iPhone app, but a thread on the Developer Forums gave me a hint:

Some companies are already providing (or planning to provide) a gateway to the APN:

These are:

Urban Airship also provide In App Purchase.

Or you can build your own: Open Source & Tutorials

I will try to keep this list updated.

Edit: added ApnsPHP & pyapns.org
Edit: separated the active services from the beta, added msgpush.com and C# Library
Edit: added a Rails plugin
Edit: added AppNotify (in Beta)
Edit: AppNotify is no more in Beta.
Edit: Added EasyAPNS source code
Edit: Removed Bigcurl HTTPush, since it’s reserved for bigcurl agency customers
Edit: added a Perl module
Edit: Removed iPushServer.com, msgpush.com, iLime and AppNotify
Edit: Added XendApp
Edit: Push.io is open to everyone