Microsoft made available on December 19 yet another tool to help non-professional progammers to build Windows apps.

Codenamed "Project Siena,' the "Metro app that creates apps" (as the folks at Surfacegeeks.net dubbed it) is available in the Windows Store as a free download.

According to the description, Siena's main target audience is "business experts, business analysts, consultants and other app imagineers."

Examples of the kinds of Metro-Style/Windows Store/modern apps that can be built using Siena include apps for navigating "media-rich product catalogs," apps for resolving customer-service issues, and apps that make use of photos, videos, pen and voice notes, tied back in to an "asset database."

"Siena works well with corporate and web data and media content: SharePoint lists, Excel and Azure tables, RSS feeds and the gamut of RESTful services," Microsoft's app-description notes.

Siena apps are built using HTML5 and JavaScript, but can be extended using one's "favorite programming tools."

Internally, Project Siena may have been known as "AppMagic." (It's not clear if that will be the final name of the app, but a quick search makes it clear a few others seem to have claims on the names "AppMagic" and "App Magic.")

Microsoft launched a beta of App Studio earlier this year in an attempt to get non-programmers to build Windows Phone apps. Microsoft also has a tool known as "LightSwitch" that targets non-professional programmers. (LightSwitch is part of Visual Studio these days.)

Seemingly in keeping with Microsoft's tradition of using place names as codenames, Siena is a city in Tuscany, Italy.