Tools for Developing VoiceXML Applications Part 2 @ XML JOURNAL

Tools for Developing VoiceXML Applications Part 2

Last year in this column (XML-J, Vol. 2, issue 2) we reviewed an initial set of VoiceXML development tools and integrated development environments (IDEs). Now we'll review some of the new tool sets developed by independent software vendors for the development and testing of dynamic speech-based components and applications.

I'll focus on how to use these tools to test and debug VoiceXML applications from a desktop-based development environment and/or a normal touch-tone-based phone.

Note/Disclaimer: This article doesn't attempt to compare the capabilities and features of the various tools, but instead provides information on the various development tools in a concise fashion. To ensure neutrality, the vendors have also been listed in alphabetical order. Even though I've tried to provide the latest and most correct information and compliance, please validate it with respect to the VoiceXML specifications through the appropriate vendors.

GetVocal VoiceXML SDK
VoiceXML SDK from GetVocal (a division of Digital Voice Technologies) is a desktop-based Visual VoiceXML development and testing tool. It supports the latest (VoiceXML 2.0 draft) version of the specification including support for XML-based grammars. It's built on top of Microsoft Speech SDK 5.1 and uses Microsoft TTS and ASR engines for text-to-speech and speech recognition.

Graphical testing and development is the key highlight of the SDK (see Figure 1), which also includes a virtual phone pad for real-phone simulation, a graphical VoiceXML generator, scripting support through JavaScript VBScript (with extensions for invoking ActiveX components and Java classes), and a complete visual debugging environment with steps, breakpoints, and variable watches.

Apart from testing local VoiceXML content, the SDK also supports visual interpretation and testing of remote/dynamic VoiceXML applications. A distinctive highlight of the SDK is that apart from the simulation through a virtual phone, it can actually use a TAPI-based interface to interact with a live phone through a voice modem or an installed dialogic card. This feature converts the SDK from a desktop-based testing tool to a full-featured single-port VoiceXML gateway. The SDK also includes a complete VoiceXML tag reference and sample VoiceXML applications.

Included with the SDK is GetVocal VoiceXML Editor, a rich editor that features syntax highlighting and configurable tag shortcuts. A time-limited evaluation version of GetVocal SDK is available for Windows 98/ME/NT/2000/XP platforms from www.getvocal.com/vxml.asp.

HeyAnita FreeSpeech Developer Network
FSDN is a hosted VoiceXML platform. The tools include integrated development environments for developing VoiceXML applications and XML-based grammars. The Web-based integrated development environment approach provides flexibility by allowing VoiceXML documents and external grammars to be stored in multiple locations: a self-managed online scratchpad, uploaded files, and external Web servers.

Applications built using the FreeSpeech Developer Network use XML grammars that are based on the Speech Recognition Grammar Specification draft available from W3C (www.w3.org/TR/speech-grammar), now part of VoiceXML 2.0 (see sidebar). To jump-start grammar development there are a couple of tools such as a wizard-based grammar generator (see Figure 2) and an online grammar parser to test utterances.

SIDE BAR
Update: VoiceXML 2.0 Draft Specification Is Now Available
In October 2001, W3C released a draft of VoiceXML 2.0. VoiceXML 1.0 was released by the VoiceXML Forum in March 2000. Some highlights of the 2.0 draft:

The W3C Voice Browser Activity (www.w3.org/voice) has officially taken over the management and technical development of the VoiceXML specification. This is a good step for the development of VoiceXML as W3C is a great standards organization. The VoiceXML Forum (www.voicexml.org) continues to focus on conformance testing and a branding program for VoiceXML.

Mandatory support for XML-based Speech Synthesis Markup Language (www.w3.org/TR/speech-synthesis).

Mandatory support for XML-based Speech Recognition Grammar Format (www.w3.org/TR/speech-grammar). This is critical as it will result in better conformance between the different vendor implementations of VoiceXML 2.0. In addition to the XML-based format, VoiceXML 2.0 implementations can optionally support the augmented BNF form of the grammar format specification as well as other formats such as JSGF.

A number of other changes have been recommended, such as changes in both elements and attributes.
END SIDE BAR

To assist in development, FSDN provides technical resources such as a VoiceXML reference, a grammar reference, FAQ, tutorials, and a prebuilt VoiceXML and grammar library. For communication between developers, FSDN includes NNTP-based threaded forums. FreeSpeech Developer Network is available at http://freespeech.heyanita.com.

IBM WebSphere Voice Toolkit
WebSphere Voice Toolkit is a desktop-based IDE that's built on top of IBM's next-generation open-source development tool platform, Eclipse (www. eclipse.org). Voice Toolkit is really written as a plug-in to the underlying core Eclipse platform. This allows Voice Toolkit to inherit the advanced IDE features provided by the open-source Eclipse IDE and IBM's commercial tools built on top of Eclipse. For instance, Voice Toolkit can inherit other Eclipse modules (plug-ins) for server-based dynamic application development with IBM WebSphere Application Developer Studio to provide an integrated server-based J2EE/VoiceXML application development with full-fledged features for J2EE application development and common IDE features such as CVS version management and project management.

For VoiceXML applications, Voice Toolkit leverages IBM Voice SDK (reviewed in this column in XML-J, Vol. 2, issue 2) to interface with desktop text-to-speech and recognition engines. This integration enables the toolkit to test the VoiceXML content in both audio and text simulation modes. In addition, Toolkit includes tools for editing and testing Java Speech Grammar Format (JSGF) and Speech Recognition Control Language (SRCL) based grammars (see Figure 3), a color-coded VoiceXML editor with a content assist feature to select elements and attributes, an audio recorder for creating and playing .au/.wav prompts, a pronunciation builder for the WebSphere VoiceXML Server/SDK, wizards for creating database-based dynamic Web applications using JSP and JavaBeans, and a voice application debugger.

WebSphere Voice Toolkit is available for Windows 2000-based operating systems from www-3.ibm.com/software/speech/enterprise/vtoolkit.html.

Telera DeVXchange AppBuilder
DeVXchange AppBuilder from Telera Inc. is a desktop-based visual VoiceXML application generation IDE. At first it gives the impression that it's a traditional IVR toolset, and even its drag-and-drop palette-building blocks don't directly map to VoiceXML elements. However, with a little bit of exposure you can understand that the tool focuses on generating the underlying dynamic scripting code in VoiceXML 1.0.

Figure 4 shows a simple menu-based dialog built using the visual tool. The bottom window shows the VoiceXML dynamically generated. In addition, the tool features integration with Visual SourceSafe for configuration management, FTP-based remote publishing, rich building blocks for a call-flow scheduler, a task balancer, logging, speech recording, variable-based call routing, database query, call transfer, call bridging, and the ability to create custom reusable blocks based on XML. The tool differs from a number of other VoiceXML IDEs as it focuses on the server-based ASP/JSP-based dynamic application generation rather than the VoiceXML template itself.

Telera AppBuilder runs on top of Windows NT/2000 platforms and requires either Microsoft Internet Information Server 4.0/5.0 and/or a JSP/servlet engine such as Apache Tomcat (included with the installation). More information about AppBuilder is available at www.telera.com/appbuilder.html.

VoiceGenie Genie IDE
Genie IDE from VoiceGenie Technologies is a desktop-based toolkit for developing and testing local and remote VoiceXML-based applications. Genie 1.0 (see Figure 5) is a full-featured environment for the interactive development of VoiceXML applications, including project management with FTP-based publishing support, syntax highlighting, indentation, a palette-like tag manipulation tool for easy tag reuse, configurable DTD support, and coding assistance through tag and attribute choices. The IDE also includes online help, sample VoiceXML files, and a step-by-step tutorial.

A distinct highlight and highly productive feature of the IDE is the wizard-based support for VoiceXML generation. Using intuitive and simple dialogs, wizards can help create both VoiceXML dialogs and forms and XML- and ABNF-based grammars. Genie 1.0 leverages technologies such as the latest VoiceGenie VoiceXML interpreter and the Microsoft SAPI interface for Text to Speech (TTS).

Apart from the development and testing of locally created .vxml files, Genie 1.0 IDE also supports the testing of remote (URL-based) VoiceXML applications. This feature can be used to test application server-based dynamic VoiceXML applications. In essence, the local IDE can be used to create the VoiceXML content template and additional dynamic scripts and tags (such as Perl/JSP/ASP/ASP.NET), then be served through a Web or application server and tested remotely. To aid the dialog flow, Genie 1.0 also provides a visual tool called "Show Dialog Flow," which constructs a simple flow diagram.

Genie IDE 1.0 is available officially for Windows 2000 (Service Pack 1). However, I tested my version on Windows XP and it was pretty stable. A 90-day evaluation copy of the Genie 1.0 IDE is available for download from http://developer.voicegenie.com/IDE.php.

Voxeo Designer
Voxeo Designer from Voxeo Corporation is a Java-based visual VoiceXML editor. It provides an integrated round-trip source and visual dialog design editor with a focus on visual representation of the dialog flow (see Figure 6). It uses a context-sensitive, palette-based toolbar for visual drag-and-drop-based VoiceXML generation. It includes online help and allows remote editing and publishing of VoiceXML content.

Designer is available for Windows platforms from http://community.voxeo.com/vd2.jsp.

Conclusion
The depth and breadth of these additional tool sets for interactive design, development, and testing of VoiceXML applications illustrates that the whole VoiceXML-based speech application development and deployment landscape is maturing, leveraging the advances and features that we've seen in the traditional Web application development space. This year we should see a boost in the world of VoiceXML, accelerated by the richness of some of these development tools and technologies. Table 1 provides a summary of the tools reviewed in this article.

Next I'll focus on how we can leverage Voice over IP (VoIP) to develop and deploy VoiceXML-based speech applications on IP-based telephony networks.

References

W3C Voice Browser Activity: www.w3.org/Voice/

VoiceXML 2.0 Draft Specification: www.w3.org/TR/voicexml20/

Related Links

About Hitesh Seth
Hitesh Seth is chief technology officer of ikigo, Inc., a provider of XML-based web-services monitoring and management software. A freelance writer and well-known speaker, he regularly writes for technology publications on VoiceXML, Web Services, J2EE and Microsoft .NET, Wireless Computing & Enterprise/B2B Integration. He is the conference chair for VoiceXML Planet Conference & Expo.