As for all such projects, the open source WBEM/CIM projects listed in Chapter 15 come with a varying level of support: ranging from the excellent to the nonexistent. Posting a question to a mailing list will allow you to gauge the activity within a project and I would advise you to monitor a group 's mailing list and attend teleconference meetings before committing yourself to a particular implementation.
Another question to consider when using open source software is how much influence your company is likely to have over the direction of the product. If you buy a commercial product then presumably you can offer additional money to the vendor to encourage the introduction of the new features you require. In the open source world, the features that you find essential may not be of interest to othersare you prepared to design and code them yourself and then release the results to the wider community?
Note that a project being open source does not mean that it is uncontrolled. The features of openPegasus, for example, are tightly controlled by a steering committee and code is released at regular intervals with the content of each release being defined and agreed in advance (in Project Enhancement Proposals (PEPS) which can be viewed on the openPegasus Web site). In addition, one of the companies represented on the steering committee provides a project manager to control the content, quality and schedule of each release. Although the results are open source, the control of the development process is probably as tight as on any other software project.