In the latest sign that open source is gaining traction in the enterprise -and among IT vendors- Sun Microsystems has announced plans to release a Linux version of its iPlanet Application Server for e-business later this year.

Sun says it's the next step in its Open Net Environment (Sun ONE) initiative, it's attempt to offer platforms and architectures that involve heterogeneous computing resources. The Linux version of iPlanet Application Server, set for a June release, will expand Sun's Linux support beyond existing versions of iPlanet Web Server for content generation, iPlanet Message Queue for integration and Forte for Java tools.

It will offer enterprises a "complete development environment on Linux," according to the company, and it should be welcome news for end-users who are building services on multiple platforms -Microsoft Windows, IBM AIX, Hewlett-Packard UX and more- and not only on Sun's own Solaris operating environment.

Sun's announcement is the latest sign that major IT vendors are apparently listening to enterprise IT executives who are trying to squeeze more value out of their existing investments and resources, and are turning to open-source Linux to help them achieve their goals.

Last week it was IBM with big enterprise Linux news, as Big Blue announced it would unveil a Linux-only mainframe to help "reduce server sprawl" and compete with midrange equipment made by Sun and Hewlett-Packard. (Read "IBM Unveils Linux-Only Mainframe')

In Sun's case, a Linux version of its iPlanet Application Server is a move to respond to the trend in the industry. The company cites an IDC report that found, during 2000, more than 25% of new license shipments for server operating systems were Linux-based, open-source systems. Sun says that by not locking developers into a single platform, it will improve developer productivity and provide enterprises with more flexibility when deploying services on demand.

"Over the past year we have seen increased demand among our customer base for Linux support. While most customers are continuing to deploy on the Solaris (operating environment) platform, they are developing on multiple platforms and we are committed to providing the robust, open foundation they need to build applications and services on demand," says Wes Wasson, vice president of iPlanet product marketing at Sun.