As a developer who spends 10+ hours a day in a browser, I've become selective about my Firefox extensions. Here are five that actually stay installed: 1. uBlock Origin — Ad/Tracker Blocking The gold standard. Blocks ads, trackers, and malicious scripts. Zero configuration needed. 2. Firefox Multi-Account Containers Isolate work, personal, and testing sessions in separate "containers" with different cookies. Essential for testing OAuth flows. 3. Vimium-FF — Keyboard Navigation Navigate tabs, links, and pages entirely from keyboard. Steep learning curve, massive productivity gain. 4. Tree Style Tab — Tab Management Vertical, tree-structured tabs for managing 50+ tabs without losing your mind. 5. Weather & Clock Dashboard — New Tab Replacement I built this one myself. When I realized I was wasting 30 seconds every morning tracking down the weather, I decided to replace my browser's blank new tab page with something actually useful.…