Fill and save passwords, find and edit items, and more. With 1Password X, you can access everything you need directly in Firefox. 1Password is a password manager that keeps you safe online.firefox keeps crashing (Mac) User Help for Mozilla Firefox.YSlow analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages. Official YSlow Open Source Project Website.After the installation is complete, you should be prompted to exit your browser. Follow the steps in the installation wizard. If you are running an Intel processor, click Mac Runtime next to 'Silverlight 3.' Otherwise, click Runtime for Mac PowerPC next to 'Silverlight 1.0.' After the download is completed, installation should start automatically.