Tabular Editor is an editor alternative to SSDT for authoring Tabular models for Analysis Services even without a workspace server.
The Tabular Editor is an open source project that can edit a BIM file without accessing to any data. This offline capability makes any change very quick to apply to the BIM file, especially when you manipulate and manage measures, calculated columns, display folders, perspectives and translations.
Tabular Editor supports the compatibility level 1200 or newer (JSON format), including the 1500 required by calculation groups.
You can download the executable and the source code from the Tabular Editor project on GitHub.