“It’s really hard to build an HTML application that talks to one database, yet IT developers have a huge backlog of requested applications that talk to multiple databases,” says Peter Yared, CEO of ActiveGrid. His company aims to solve that problem, in part by doing away with the traditional three-tiered model of Web application development.

Yared’s team saw that companies such as Google and Yahoo were running Web-oriented “mashup” apps off of inexpensive servers, using the so-called LAMP (Linux, Apache, MySQL, Perl/PHP/Python) stack. Added to the mix were technologies such as AJAX (Asynchronous JavaScript and XML), BPEL (Business Process Execution Language), and WSDL (Web Services Definition Language), which helped decouple applications from data sources using the abstraction principles commonly associated with SOA.

ActiveGrid saw opportunity in this trend. “We productized the best-of-breed development processes,” Yared recalls.

But ActiveGrid is not an SOA platform, at least not in the sense most enterprises mean. “You don’t need a message bus. Applications can call parameters, RSS, and so on, directly,” Yared says. That’s because the applications don’t need long-lived data integration; ActiveGrid’s technology is meant to develop applications, such as dashboards, that rely on currently polled data, rather than interacting with data whose states need to be reconciled. “It’s more ad hoc,” Yared says.

ActiveGrid’s application builder and application server rest on widely used open source technologies, but LAMP isn’t the end of the story. The company has developed unique, enterprise-level functions that enable the open source technology to work well in real enterprise environments. For example, ActiveGrid

Click for larger view.

provides session replication, graphical design of Web page flow, the ability to drop AJAX components onto forms, and back-end integration with identity management systems. The latter technology allows ActiveGrid applications to dynamically adapt the user interface, application flows, caching, and session management to the user’s role, based on what’s defined in the identity servers.

ActiveGrid also automatically caches Web service results based on user roles, with options to allow the cache to be bypassed so only critical connections go through the back-end system when necessary. That’s meant to keep the applications lightweight but savvy about access issues, Yared says.

Lightweight Web development has taken the enterprise by storm. Active­Grid has created a solution dedicated to maintaining that agility while adding a stack of SOA-style value.