This is a quick guide to the Java properties which can be set to influence ABCL's behaviour.

abcl.specials.initialSize	Determines the number of slots available for dynamic special variables. Default value: 4096, same as SBCL.
abcl.specials.grow.delta	When not enough slots are available, ABCL will grow the number of available slots by this amount. Default value: 1024.
abcl.specials.grow.slowly	When defined, ABCL will run the garbage collector before growing the number of special slots. If the GC invocation frees slots, those will be used instead of growing the maximum number.