Squid-2.5 internal changes

Everything is now automake'ed
Dependency checking is properly implemented
Current modules are implemented cleaner
Even more GNU software is needed by the developers 

Compiles cleanly under cygwin
Native windows compiling port is underway
Squid's internals aren't very windows-native-friendly

Large amounts of code tidyups
Runs without strange crashes on various strange platforms
Linux / S/390

Improved load spike recovery
(2.4 and 2.5) storage manager will trade disk hits for throughput to prevent squid spiralling into death during peak periods
Squid-2.2 and squid-2.3 can suffer from this
max_open_disk_fds in squid.conf can be used to place a hard limit on the number of open disk files

2.5 is stable
Personally being run at a handful of places under moderate load
No observable crashes, periods of unavailability
Uptimes would be high if not for the SNMP/FTP bugs :-)