Tasks chromatic has identified as necessary and will do, will help someone do, or will document in sufficient detail that someone else can do part or all of them:

• ClassVtableOverrides
• Merge Context and CallSignature PMCs
• Enable bytecode migration between (supported) bytecode versions
• Fix annotation storage, indexing, and line numbers
• Move GC flags out of PMC headers
• Add write barriers for the GC
• Delay MMD registration until the first creation of a PMC with MMD candidates
• Improve performance and storage and lookup of class and object attributes
• Implement the sweep-free linked list GC
• Define necessary ops for Lorito
• Deprecate mutable STRINGs
• Deprecate NULL STRING pointers in public API
• Create language and engine for PAST/POST optimizations
• Replace IMCC with PIRC