Customizable and Extensible Server Management Panel
Has all of the best open-source technologies ready to deploy on command. Free Softaculous included. Excellent when customized and packaged as deployable template.
Its the best thing on the market of it's kind and Softaculous/Webuzo/Virtualizor do a wonderful job of keeping their products updated - there could be more knowledgebase documentation, but what is there is perfectly sufficient to get your project completed.