Open up FDS?

Adobe announced that it will open source the strip down version of LiveCycle Data Service called BlazeDS. From what I heard, BlazeDS provides AMF3 remoting without data management and its data push solution is not so scalable as LCDS. (features comparsion chart). The reason is that BlazeDB still uses the blocking IO to handle connections whereas LCDS uses Java NIO. The power of Java NIO is that the server thread will not be held up for the connection during the request is in process. (Detail here). So, BlazeDB is only good for tasting the power of AMG remoting and learning how AMG protocol being implemented.

Future of GraniteDS

However, if all you need a solid AMF solution to connect Flex 2 with Java, take a look at GraniteDS. I heard that it does a great job. However, GraniteDS may become obsolete soon as the founder, Franck Wolff, seemed a bit caught off guard and unsure what the future held for GraniteDS. However, finally he decided to continue GDS development. Here are why GDS is still better than BlazeDS:

1. BlazeDS does not offer any data management features.
2. FDS/LCDS has it own (proprietary and closed) data management system, offers (officially supported?) service factories for Spring and Hibernate (but without any lazy-loading support) and is, say, expensive.
3. GraniteDS integrates with known enterprise J2EE persistence systems such as EJB3 (session and entity beans with full lazy-loading support) and with wildly used and open source frameworks such as Spring (with Acegi security) or JBoss/Seam (with conversation scope support - new, coming in the next release).
4. GraniteDS provides a fast and powerful ActionScript3 code generator (Gas3): you just have to write your database model (EJB3 entity beans), Gas3 will generate corresponding ActionScript3 beans and Hibernate code generation tools will create your database tables. So, from an enterprise point of view, GraniteDS does not really compare to BlazeDS and, on the other hand, it seems to be still a powerful and free alternative to FDS/LCDS.

Update: GraniteDS 1.0 is released. Here is an article that discusses this release.

How about WebORB?

I also heard that WebORB is a powerful alternative to LCDS (compare them here). Again it is Free! However, it is not open source and its license may constraint you doing some interesting things. I will check this out more. However, here is a promising comment from the director of scrapblog.com - a fancy Flex example on Web. "Scrapblog.com needed a remoting solution to use with Flex 2, as it currently only supports Java. I didn’t think twice when choosing WebORB for this task. Version 3.0 [of WebORB] is simply amazing. You won’t experience the flexibility and responsiveness that WebORB offers with any other remoting solution. My hat goes off to Midnightcoders, keep the great work." - Omar Ramos, Scrapblog’s Director of R&D.