Versions:
0.1-
Texture Pack Started
Enderman is a Slenderman

0.2-
New Lava texture
New Emerald Block texture
New Iron block texture
New Gold block texture
New Diamond block texture

0.3-
Ore textures changed

0.4-
Improved sword textures

0.4.5-
Christmas Edition
Grass is white as if it snowed same with leaves,vines, and grass

0.5-
Pickaxes have a new texture

0.6-
New Creeper Texture

0.7-
Cobblestone Improved

0.8-
Improved grass texture
Improved Dirt Texture

0.9-
CTM glass support

1.0-
The rest of the blocks in the page were changed

1.1-
Added a few secret textures

1.2-
Ores have been changed

1.3-
Changed a whole lot of items, blocks and more!

1.4-
Few Ore changes and stone changes

1.5-
New Cobblestone texture
New Stone texture
New Stonebrick textures
New Lapis Block texture
New Nether Quartz textures

1.6-
Paintings are now themed to the pack.

1.7-
A new x32 version (Work in Progress) (Possibly a x64 version later)(Later removed)
A few blocks were changed
Sandstone, Sandstone Smooth, Sandstone Chiseled, Cobweb, Beacon, Wood Planks, and more
SlenderCraft on the main menu improved
Clouds have been added
Natural Texture Enchancments
CTM temporarily unsupported

1.7.1-
1.6 Ready
New Water and Lava animation
New Fonts
Removed x32 Version
Lang files edits
Fixed Slenderman's Head Glowing without Optifine

1.8-
New leaves textures
Biome specific coloring
New sounds Slendermen has noisy static noises and walking sounds
Splashes

1.9-
CTM Support
New Splashes
Slenderman's tie is now black
Fixed Torch Texture
Paper is now called Page
Paper Texture Changed
Custom Skies
New CreepyDark Edition of the Pack

1.10-
Removed sun texture from CreepyDark edition
Icon changes
New CTM textures
New Wood Plank textures
New Nether Textures
Enchanced Command Block texture animation
Brightened Lava
Brightened Fire
New Glowstone Texture
New Mushroom Textures
New Zombie Texture
Improved Camera effect
Improved Water texture
Few More Splashes
Language edits
New Eye of Ender texture and is named 'Slender's Eye'
New Ender Pearl texture and is named 'Slender's Pearl'
New Ender Chest texture and is named 'Slender Chest'
The End is now called Slender's Realm
New GUI
New Farmland textures
New EnderDragon Texture and named 'Slender Dragon'
New Ender Crystal Texture
New End Textures and end stone named 'Slender Stone'
Improved Mossy Stone texture
New Background texture
New Panorama in main screen