Tabular Editor is an editor alternative to SSDT for authoring Tabular models for Analysis Services even without a workspace server.  Free download

DAX Editor is an extension of SSDT that makes it easier to edit DAX measures in a Microsoft Analysis Services Tabular project.  Free download

SSAS Tabular Translator is an editor for the JSON translation files exported and imported by SQL Server Data Tools, for a Tabular model compatibility version 1200 or later.  Free download

SSAS Events Analyzer is a simple monitoring system that can be easily applied to any SSAS server with minimal effort.  Free download

SSAS Activity Monitor is an open source tool to monitor the current activity (sessions, transactions, connections, and locks) on an Analysis Services instance. It works for both the Tabular and Multidimensional mode.  Free download

MDX Studio is a tool that was developed by Mosha Pasumansky, a former Analysis Services developer. This tool is invaluable when writing a MDX query: you have a code formatting feature, an embedded system to analyze query performance and many…  Free download