Commercial
Open Source
- Enterprise Java XACML
- ForgeRock OpenAM
- HERAS-AF
- PERMIS
- PicketBox
- SICSACML
- SunXACML
- WSO2 Identity Server
- xacml4j
- XACML Light
- XEngine
Embedded
- EMC (partial, internal only)
- eXist
- Oracle Entitlements Server
- Oracle WebLogic
- IBM Tivoli Security Policy Manager
- Sun OpenSSO Enterprise
If I missed an implementation, feel free to leave a comment and I will add it.
Secure Cloud Development 
I think it would be most useful to learn which version(s) of XACML are supported by each of these vendors.
Eg I know that Axiomatics, Quest (BitKOO) and eNitiatives offer v3 support and that most probably they’re the only three that do, but is this up-to-date information ?
You left out SICSACML. Info here: http://www.sics.se/node/2465
Thanks, I added it to the list.