Starting with v7.34.0, source code package does not include source of GleamTech.Common (formerly named GleamTech.Core before v7.35.0).
This is because needing to include both signed and unsigned DLLs was increasing the package size. For example, if we include only signed GleamTech.DocumentUltimate then it can’t reference the unsigned DLL produced by GleamTech.Common project. So all DLLs need to be signed. Unsigned DLLs can reference signed ones but not vice versa.
Also GleamTech.Common, includes stuff like license logic and it’s not meant to be modified by users. So you shouldn’t be worried, GleamTech.FileVista, GleamTech.FileVista.Core and GleamTech.FileUltimate projects are sufficient to do modifications. GleamTech.Common is just a utility project which everything depends on (think it like Newtonsoft.Json)
Regarding "support our own custom file storage provider"; this is possible by inheriting abstract classes GleamTech.FileSystems.FileSystem and GleamTech.FileSystems.Location. We can provide source code of PhysicalFileSystem, AmazonS3FileSystem etc for reference.