ESRI, a leading GIS software provider, has released a public version of its ArcGIS JavaScript API that allows developers to integrate GIS functionality with web applications. The API works with RESTful services from ESRI's recently released ArcGIS Server 9.3 and there are also Javascript extensions for use with Google Maps and Microsoft Virtual Earth.

According to ESRI:

You can use the ArcGIS JavaScript API to bring maps and tasks from ArcGIS Server into your web applications. For example, you can: Display an interactive map of your own data

Execute a GIS model on the server and display the results

Display your data on an ArcGIS Online base map

Search for features or attributes in your GIS data and display the results

Search for addresses and display the results

Our API directory now includes an ArcGIS JavaScript API profile with additional details. You can also familiarize yourself with the API through ESRI's API Reference pages as well as Samples and a set of "community" pages.

Developers familiar with the Dojo JavaScript Toolkit will be keen to know that the ArcGIS JavaScript API is built on the Dojo toolkit, thereby providing access to the various Dojo tools including dijits (widgets).

The JavaScript extensions provide a great option for developers looking to tap into the best of both worlds. Google Maps Mania and Mapperz have both covered the Google Maps extension, and additional information on the Virtual Earth extension is available from Virtual Earth, an Evangelist's Blog.

With the release of this API, ESRI has ventured forth to make the integration of GIS web services much more accessible to the general public. There is one catch, however. Unless you or your organization have implemented ArcGIS Server 9.3, you will need to rely on other implementations of ArcGIS Server that have been exposed as RESTful web services. This means that to truly integrate GIS functionality customized for your own needs, you will need to have access to your own ArcGIS Server instance.

ESRI does provide some sample servers that can be used as testbeds for learning the API, and the ArcGIS Online services (a suite of different geospatial web services) can also be consumed via the API.

The release of this API has been long awaited by developers in the GIS community, and it's a good first step towards leveraging the robust and sophisticated GIS capabilities of ArcGIS Server for use in web applications. The JavaScript extensions are a welcome addition to the ever-growing JavaScript tool set for map mashup developers, and it will be interesting to see how map mashups evolve as the ability to integrate this type of GIS functionality increases.

Mapping APIs continue to be popular, and this new API is a welcome addition to the 60+ mapping APIs already listed in our directory.