BrowserStack is a cloud-based cross-browser testing tool that enables developers to test their websites across various browsers on different operating systems and mobile devices. That includes local testing.
They sponsor free subscriptions for the DokuWiki project. Regular DokuWiki contributors (core, plugins or templates) can apply for a free subscription by sending a simple email to Anika. Please state if you would like access to their Live, Automate, Screenshots service or a combination of those.