Excel Add-In for PowerPivot and Analysis Services Tabular projects that will include an Object Browser, query editing and execution, formula and measure editing ,syntax highlighting, integrated tracing and query execution breakdowns.DAX Studio
It is developed and maintained by a team of volunteers. If you have any feedback, recommendations or issues with DAX Studio, please add them to this project site.
Discussions - http://daxstudio.codeplex.com/discussions
Issues - http://daxstudio.codeplex.com/workitem/list/basic