IBM, Siebel Systems and HP weighed in Tuesday with renewed support for businesses building a service-oriented architecture, adding new software, services and support centers.

In an SOA, IT applications are loosely linked as "services," providing functions based on commonly agreed interfaces. The elements of the overall architecture can be replaced independently of one another. However, different companies define SOAs -- and the necessary interfaces -- in different ways, making conception and integration of such an architecture challenging.

HP is offering to help businesses with this challenge with the launch of a range of new SOA consulting services and the opening of four SOA competency centers. The services will help businesses with everything from envisioning an SOA to developing and running it, HP said. Four new competency centers, in Bangalore, India; Sophia Antipolis, France; Atlanta and Tokyo, will give customers better access to experts from HP and other companies who can help them build their SOA, HP said.

For its part, IBM said it will lend its support to its business partners and independent software vendors and systems integrators who are building SOAs for their customers. The support will include free access to IBM training and marketing resources through its PartnerWorld Industry Networks, it said. Among the free training resources on offer is a three-day online learning session called Architecture Hotline which aims to teach ISVs and integrators to implement an SOA -- but only by using IBM software.

That still leaves some companies needing to build bridges to other applications. For those looking to link IBM and Siebel software together, Siebel is readying an upgrade to its Web User Interface Dynamic Developer Kit. Version 7.8 of the kit will allow access to Siebel applications through an IBM WebSphere Portal. This means developers will be able to build composite applications, linking Siebel software together with DB2, WebSphere, Tivoli and more, Siebel said. The company will reveal more details of the upgrade in July, it said.

The IDG News Service is a Network World affiliate.