With Athens the TList and other classes Items property is moved from Integer (32-bit on any platform) to NativeInt (32 or 64-bits, depend by platform).
In QuickLib, for example Quick.Threads.TThreadObjectList the property Items use Index: Integer, so during a 64-bit compilation a
warning message is shown:
[dcc64 Warning] Quick.Threads.pas(132): W1075 Overloading a similar index type by declaring an array property 'Items'
Quick.Threads.pas(132): Related member: property TThreadObjectList<T>.Items[Integer]: T;
Quick.Threads.pas(132): Related member: property TList<T>.Items[NativeInt]: T;