Back before 1.3, one of my favourite packs was Jungle Ruins. It catered to my love of primitive technology and really held me with it's rough, organic equipment...unfortunately, it was incomplete and appears to have not been updated since beta 1.8 or so.

My primitive pack is somewhat "inspired" by jungle ruins, although it aims more at being just generally "primal" more so than "jungle-y".

Wood and Stone swords are now roughly made spears. Iron is a machete, and diamond has been made into an aztec macuahuitl. The other tools have simply been transformed to look more primitive, such as shovels being more of material-tipped digging sticks. Mineral-based armours have been changed to look like they used less material to create and leather looks more like primitive brain-tanned leather rather than the typical and more advanced cuir bouilli armours of packs like Doku.

>>wood planks are now split rails lashed together with leather cordage.

>>cobble variants have a "deeper" texture to them, and the stones are more angular like real dry-stone masonry

>>dirt is more of a sandy loam than default

>>Wheat has been changed into grain amaranth

>>new ores

>>new terrain overall

>>Brighter coloured, better, plants

>>sexy dandelions