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This FAQ concerns only EmbassyOS version 0.3.0 and above. For v0.2.x documentation, please see our Service Packaging Guide.
The application can be written in any language, so you may prefer to select an application in a language you are comfortable with (or write your own application). It is only important that the packaging specifications be followed.
With sufficient effort, most any software with the ability to be self-hosted could make its way onto EmbassyOS. That being said, the following features will make service packaging much easier:
Already built with self-hosting in mind
Active development / community
Native proxy/tor support
JSON, TOML, or YAML are valid options.
There is something either missing or incorrect in regard to one of the