Original: It owns two taxable for-profit subsidiaries: the Mozilla Corporation, which employs several Mozilla developers and coordinates releases of the Mozilla Firefox web browser, and Mozilla Messaging, Inc., which primarily develops the Mozilla Thunderbird email client.
Simplified: It owns two taxable for-profit subsidiaries: the Mozilla Corporation, which employs several Mozilla developers and sets releases of the Mozilla Firefox web browser, and Mozilla Messaging, Inc., which creates the Mozilla Thunderbird email client.