Add gerbera

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``- [Name](http://homepage/) - Short description, less than 250 characters. ([Demo](http://url.to/demo), [Source Code](http://url.of/source/code), [Clients](https://url.to/list/of/related/clients-or-apps)) `License` `Language` ``

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``- [Name](http://homepage/) `⊘ Proprietary` - Short description, less than 250 characters. ([Demo](http://url.to/demo), [Source Code](http://url.of/source/code), [Clients](https://url.to/list/of/related/clients-or-apps)) `Language` ``


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