What are some alternatives?
When comparing Mmock and soapUI, you can also consider the following products
Postman - The Collaboration Platform for API Development
Sauce Labs - Test mobile or web apps instantly across 700+ browser/OS/device platform combinations - without infrastructure setup.
Paw.cloud - Paw is a REST client for Mac.
TestComplete - TestComplete Desktop, Web, and Mobile helps you create repeatable and accurate automated tests across multiple devices, platforms, and environments easily and quickly.
Runscope - Log, monitor and measure your API usage to solve API problems fast.
Ranorex Studio - Accelerate testing with Ranorex Studio, the all-in-one tool for test automation. For desktop, web, or mobile app testing, with easy codeless automation tools, a full IDE, robust object recognition, flexible reporting and built-in Selenium WebDriver.