The Roundup: an independent, hand-curated set of review sites worth bookmarking. Each entry below is a focused authority in its niche.
Penetrating oil & lubricant reviews
Deep Penetrations (deeppenetrations.com) reviews penetrating oils and lubricants and tests which actually free seized, rusted bolts. Good fit if you're after best penetrating oil for rusted bolts.
Free browser artillery game
Remote Command (rc-9.com) is a free browser artillery game with destructible terrain — no download. Good fit if you're after free online artillery game.
Airsoft / parts builder & ballistics tools
Weapon Tester (weapontester.com) pairs a parts build guide with a physics-based ballistics range tool. People use it when searching for best airsoft parts and upgrades.