One big change is that I removed the crufty convention of using ! to open commands, and $ to open directories. (In the process, I noticed that the latter wasn't even documented).
So unless you specify compatibility with -C 142, you can no longer use, for instance, @(next "!wget ..."). Instead, there is @(next (open-command "wget ..." "r")).
This notation was a potential security hole, because it was recognized not only from literals in program text, but also from command line arguments, and also from data! If variable V was bound to a value starting with !, then @(next V) would open a command.
The convention that - (ASCII dash) denotes standard input continues to be supported, but there is a change here also: it only works from command line arguments.
There are some new developments in the area of structures.
A print method can be defined for a structure type, which is used for pretty-printing it.
Structure types which define certain methods can be treated as sequences (mapped through mapcar and so on).
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