What is apollo?
runtime that allows devs to use (flash/flex/html/ajax) to build desktop RIAs
filesystem access
custom chrome
detect network (or lack thereof)

team need/pain
light-weight scrum tool for distributed and mobile (offline) teams
cross-platform

why not ajax?
offline
filesystem access
features (camera)
not in a browser

But, apollo plays with ajax if you want to

[maptacular demo]

combining apollo and rails
communicate from flash side using AMF serialization
REST

gotchas
Flex'isms
REST - use _method hacks for PUT DELETE HEAD; pass body on everything other than GET
Use POST with _method hacks
Use URLLoader to get HTTP Status Codes
Don't dasherize (ie don't use rails's to_xml), build your own xml using builder templates
Migrating to newer apollo builds (eg ApolloApplication vs Application)

http://labs.adobe.com/wiki/index.php/Apollo:Documentation

PPK hits the nail right on the head when describing the knowledge gap between web developers and software developers, w/r/t writing AJAX apps

For at least a year I've been worried about the total lack of relation between JavaScript and "serious" programmers. Unfortunately it seems as if JavaScript is still beneath their notice. That starts to annoy me.

The advent of Ajax makes a solution to this problem mandatory. Who will create the Ajax applications? Those who don't know how to write an application, or those who don't know the language the application will be written in?

The gap is slowly being filled by a new class of developers. Ryank is a great example of a web dev with software chops, and both evan and brad are true computer-scientists who don't feel the need to hold their noses while writing kick-ass JavaScript apps.