Those of you who host IF games on your website for play in a browser, take note. Flaxo is a new Flash-based z-code interpreter, and makes a nice alternative to the various Java interpreters. It's under development, which in this case means the save, restore, undo, and restart commands don't yet work.
Glulxe 0.4.3 is the latest update to Andrew Plotkin's reference interpreter for games using the Glulx virtual machine. It fixes a few bugs and adds the option of making sure a game doesn't try to read from or write to invalid memory addresses at the cost of a slowdown in execution.