I've been hearing a bit about Voxeo recently, so decided to take a look. Voxeo have a nice development and hosting product for VoiceXML applications, and their own hosting system uses Dialogic hardware. The online tools allow you to write and test apps using VoiceXML 2.0/2.1, CCXML and their own CallXML. You can dial-in to test your apps via phone line, or using free systems like Skype and FWD.

Also, they have a rather nice downloadable product called Prophecy, that allows you to set-up your own Windows server, and using Dialogic hardware to provide the telephony, you can have your own self-contained VoiceXML test system. They provide 2 ports in a free licence package, then you can buy more ports when you want to create a production system. It's pretty easy to install and license, and compared to some of the VoiceXML tools I have seen in the past it looked quite slick.