For those of you working in the voice space, what are you using as your IVR platform? I am using Microsoft Speech Server 2007. What are some equivalent packages? Is anyone using open source software for handling inbound or outbound calls? Note that I'm not just talking about speech recognition, which is one component of a comprehensive package. An IVR platform would consist of speech recognition, text-to-speech, a VUI technology such as VoiceXML, and call termination via SIP or telephony hardware.
You can check out Asterix - http://www.asterisk.org/ for an open source solution.
I believe that Nuance (recently merged with VoiceGenie) is the leading IVR platform with significantly more traction in the industry than Microsoft's Speech Server. You can read more about it the wiki article.
I'm not sure what to say about it with out sounding like a salesman, but I worked with it for several years and enjoyed it. My company at the time evaluated Microsoft's offering, but did not consider it mature enough to consider moving away from the Nuance / VoiceGenie product.
From a commercial standpoint, you may wish to check out Genesys. Comparatively, I'm not sure how it stands up against other commercial solutions, but my company has been using it successfully and with great results since 2005. Although I mostly work on the IVR-side of the implementation, the system tends to be very stable and relatively easy to maintain.
I have successfully tried Asterisk with Lumenvox for a speech recognition IVR. Asterisk is very flexible when it comes to IVRs and not just that. It also supports a wide range of VoIP protocols (SIP, H323, IAX ... ) and also classical telephony (T1, E1, FXO, FXS, etc) with the help of interface cards from Digium and other suppliers (Sangoma, Rhino, etc). You can find more info about Asterisk at http://www.voip-info.org/wiki/view/Asterisk
Asterisk is an open source software PBX that runs primarily on Linux. http://www.asterisk.org/
Lumenvox speech engine is a commercial speech recognition solution http://www.lumenvox.com/
Digium, Sangoma, and Rhino are telephony card manufacturers that are compatiible with Asterisk. http://www.digium.com/ http://www.sangoma.com/ http://www.rhinoequipment.com/
Depends whether you are in the self serve market or the Call center head routing market.
For the self directed apps, you can try out Genesys Stack. They have a good solution mix with a bunch of BYOB options for your own plugins. Works well for a large volume, transaction based financial services application.
If you are Call center oriented and have parts of the Cisco stack, you can try out their IPCC soltuion whcih works well with a for dummies kind of UI screen.
I've been using Voxeo for a while. It's great. They have amazing technical support, and a fully-functioning 2-line demo account. They have very nice debugging tools and free support even if you have a free account. All of their employees know and understand VoiceXML. Highly recommended.
There are a few major players I've looked at or worked with:
Voxeo: Early versions used the Nuance ASR but I believe they use their own now. Uses VoiceXML and CCXML for call control. They get expensive as you scale up but the development license (2 ports) is free.
Loquendo: I only list this because a) I did demo it and b) they have the best TTS engine I've ever heard. Seriously worth a demo just to hear the quality.
Nuance Voice Platform (NVP): I work with this almost daily. Nuance has by far the most powerful ASR on the market but it comes at a big price. If you have to ask about price then don't bother falling in love with the quality of the engine. It uses a somewhat tweaked version of VoiceXML.
Microsoft Speech Server: You already know this one of course. Bang for the buck it is a wonderful platform. The VoiceXML support is borderline (limited control over the engine from VXML properties) but if you're willing to use Workflows instead you can do just about anything you want. The ASR is good although it doesn't have near the accuracy with large or complex grammars like Nuance. This is currently my preferred platform for most applications. And like Voxeo the Developer license is free.
I would recommend Katalina 'VoiceGuide' - a windows-based CTI, IVR and dialler system at a reasonable price, supporting both tradtional POTS/ISDN telephony cards and VoIP. see: www.voiceguide.com
We are currently building a video ivr and have tried a bunch of platforms.
- Genesys - one of the few that supports video. I am not happy with this platform due to the bad video support, cumborsome web management and overall complexity.
- Voxpilot - also a one that supports video and so far perfoms better than Genesys. There is a free trial version you can download, along with some good VoiceXML examples that demonstrate the video IVR capabilities
Voxeo - just demoed it, works for IVR only (no IVVR like genesys and voxpilot)
Nuance - ASR and TTS which is pretty nice
Speechwork and Scansoft - I guess those merged (not very sure). It is a decent TTS and ASR server
Asterisk - can do IVR and IVVR with some extensions, but we use it for call management. A great piece of software.
I haven't found a good IVVR platform that satisfies all of our needs.
I previously used Telesage to run hundreds of thousands interactive surveys. It's decent software, and our support was good, but their system wasn't designed for our type of work.
We dabbled with asterisk.
For my next project, I intend to use the hosted Twilio (http://www.twilio.com/)
At my place of work we used to use Genesys, but we changed to Nortel for CTI & TAPI, and IBM WebSphere Voice Response for the user experience. I haven't developed IVR stuff for the other platforms so I can't really say if this one is better than the others, but I can say that our IVR gets a ton of calls and it is rock solid.