There are some experimental features in orphaned/experimental branches that may be worthy of adding to mainstream released code:

• Backtrace
  • Linux (implemented in Add WeakRefPtr to Foundation #2246 #2247 )
  • other platforms
• LeakDetector; handy for small scope memory leaks detection
  • Windows (works, but needs a bit more effort to be production-quality)
  • other platforms
• WeakPtr (Poco:AutoPtr weak companion) - maybe, i'm not sure it is worth it given that we should move towards std smart pointers, but there's a lot of AutoPtr usage in Poco and it wil be with us for some time); this brings in a fundamental AutoPtr reference counting change, see Add WeakRefPtr to Foundation #2246 #2247