Inspired by the work-in-progress open source OpenTomb project, Tomb Raider modder XProger has spent the past several months working on their own browser-based version of the '96 original Tomb Raider named OpenLara. It's now playable in both third and first person view. 

As an engine remake, OpenLara does not recreate the entire game however its City of Vilcabamba level (level two) can be played right now—complete with bloodthirsty wolfpacks, underwater tunnel systems, and ferocious bears. A "browse level" function does however let you load the game's other levels, but I've spent all of my time with OpenLara attempting to relearn its stop/start running-jumping-ledge-catching mechanics which seem entirely archaic today. 

Nonetheless, touring Lara Croft around familiar levels at higher than ever framerates—the original was locked at 30 FPS—is great fun, particularly when you can do so instantly from your browser. The ability to switch to first-person is also a nice touch and makes grizzly encounters and acrobatic leaps that little bit scarier.    

More information on the OpenLara project can be found via this TombRaider forum thread, and can be played in-browser over here