This week were released:
AMF3 specification
Action Message Format (AMF) is a compact binary format that is used to
ActionScript object graphs. Once serialized an AMF encoded object graph
to persist and retrieve the public state of an application across sessions or
endpoints to communicate through the exchange of strongly typed data.
And Java-Remoting BlazeDS Beta
BlazeDS is the server-based Java remoting and web messaging technology that enables developers to easily connect to back-end distributed data and push data in real-time to Adobe Flex and Adobe AIR applications for more responsive rich Internet application (RIA) experiences.
Previously available only as part of Adobe LiveCycle Data Services ES, Adobe is announcing its plans to contribute the proven BlazeDS technologies to the community under the LGPL v3. BlazeDS gives the rapidly growing Adobe developer community free access to the powerful remoting and messaging technologies developed by Adobe.
The source code will be available for download in early 2008.
In short: more AMF servers for free, other than RED5