All these companies business model is to open source their software and charge for services.
Open Source companies to watch:
Cleversafe – Grid file system.
Digium – Open Source PBX – Asterix.
Hyperic – Platform for managing heterogeneous IT environments.
Optaros – Helping enterprises choose open source solutions.
Qlusters – System management platform.
rPath – Preconfigured, pretested application appliances that can be downloaded and deployed by enterprise users in minutes.
WSO2 – Tungsten, an Apache-based open source application server built from the ground up to handle Web services.
Sahana – Sri Lanka-based nonprofit committed to promoting open source software development.
Zenoss – Network and systems-monitoring software.
Zmanda – AMANDA backup utility software.
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