Plug: I offer an ironclad and very popular Master Services Agreement at https://msabundle.com along with other legal document templates. Similar set to what Axdraft has, but instead of being customizable via online wizard, I give you annotated source documents that you can fill out and edit to your heart's content.
Backstory: When I sold Hashrocket in 2011, I added a clause to the sale agreement that let me keep all the legal IP that I had developed over the years. A little bit after that I carefully prepared my well-honed MSA contract into a template bundle with different formats and annotations. Over the years I added more templates based on documents I've actually used in my businesses. It's a nice little passive income project.