Additions

Export BitReader and BitWriter for use in custom datatypes
Fully adopt the pack-config system. Previous settings using the shared table no longer work. See docs for details
Optional lengthType argument for Pack.Map
Adds the DisableReadProtection property to Packets that stops Pack from raising an error if the entire packet wasn't read
Frac datatype that stores a number between [0–1] with fixed precision
Datatype for NumberSequence and ColorSequence
Adds Pack.Nil as an Alias for Pack.Null

Changes

To get an exported internal library, you now must call the corresponding method, instead of using the dot operator. E.g., Pack:GetWriter()
Rewrites Writer and BitWriter to use dynamic resizing, instead of using a Builder architecture. This will result in faster writer performance
Enforces consistent behavior for BufferFixed and StringFixed. They will now raise an error on length mismatch even while not in debug mode
[BREAKING]: Simplifies the vector datatypes. Pack.Vector3 and Pack.Vector2 have dynamic constructors, meaning Pack.Vector3 is equivalent to Pack.Vector3float32, and the other vector types can be obtained by calling Pack.Vector3 as a function: Pack.Vector3(Pack.Float16). If you were using the Vector3 and Vector2 alias, you do not need to change anything, Otherwise if you were using Pack.Vector3floatxx you will need to update that. This dynamic constructor allows creating a Vector3 from any numeric datatypes
[BREAKING]: Makes Vector3int16 and Vector2int16 use the actual Roblox datatypes for this. To get the old behavior, use Pack.Vector3(Pack.Int16) / Pack.Vector2(Pack.Int16)

Full Changelog: v0.8.0...v0.9.0