API Testing tools

• postman - newman open source command line runner and jetpacks
• runscope - SaaS with free plan
• chakram - node.js REST API test framework blog post
• airborne - Ruby RSpec API testing framework
• Behat - PHP BDD framework
• rest-assured - Java DSL for API testing
• vigia- Ruby API Blueprint/RAML API integration testing
• dredd - node.js API Blueprint API validation tool
• apivore - Ruby API Swagger testing

Mock server

• wiremock - Java mock web server
• api-mock - API Blueprint node.js mock web server

Proxy

• proxifier - windows/mac proxy app
• charles - windows/mac/linux proxy app