Protractor can work with any test framework that is adapted here.

Each file details the adapter for one test framework. Each file must export a run function with the interface:

/**
 * @param {Runner} runner The Protractor runner instance.
 * @param {Array.<string>} specs A list of absolute filenames.
 * @return {q.Promise} Promise resolved with the test results
 */
exports.run = function(runner, specs)

• runner.emit must be called with testPass and testFail messages.

• runner.runTestPreparer must be called before any tests are run.

• runner.getConfig().onComplete must be called when tests are finished.

• The returned promise must be resolved when tests are finished and it should return a results object. This object must have a failedCount property and optionally a specResults object of the following structure:

  specResults = [{
    description: string,
    assertions: [{
      passed: boolean,
      errorMsg: string,
      stackTrace: string 
    }],
    duration: integer
  }]

If you have created/adapted a custom framework and want it added to Protractor core please send a PR so it can evaluated for addition as an official supported framework. In the meantime you can instruct Protractor to use your own framework via the config file:

exports.config = {
  // set to "custom" instead of jasmine/jasmine2/mocha/cucumber.
  framework: 'custom',
  // path relative to the current config file
  frameworkPath: './frameworks/my_custom_jasmine.js',
};

More on this at referenceConf "The test framework" section.

Disclaimer: current framework interface can change without a major version bump.