Other than companies which are purely open source software providers (along with services) such as Red Hat and Mandrake, these are companies who support their software and/or hardware for use with open source software, typically Linux.
- Computer Associates - consulting
- Hewlett-Packard - hardware, some software, support, and consultation services
- IBM - diverse hardware and software, support, consultation services
- Oracle - database and application servers
- PeopleSoft - enterprise internet/intranet applications
- Sun Microsystems - software and hardware, although their genuine commitment to open source is in doubt by the community