XML gateways

If you're interested in learning more about XML gateways, 2 vendors provide reasonably detailed information. The technical documentation of CISCO's products is available online, both for their AON and ACE (ex-Reactivity) products. And IBM provides 4 Redbooks that go into quite some detail on DataPower. But other vendors such as Cast Iron, Layer7, Vordel and Intel (ex-Sarvega) all seem to consider their docs as a valuable assets not to be shared with the world.