uLisp Version 1.3 adds setf, allowing you to modify lists in place. It provides a way to perform operations using lists as index-addressible arrays, and use association lists for efficient data storage. The other in-place operations push, pop, incf, and decf have also been extended in the same way. For more details see Language reference.
There are also fixes for two bugs that affected append with null arguments, and with-spi.