Interpreter

Explanation of tables
*green Function exists in octave 2.0.x
Noted incompatibilities and missing features
+yellow Function exists in matcompat
Author and home for the function.
?orange Function doesn't exist
Explanation of what you can do instead.
xred Function doesn't exist, and no work-around

Help
*help
xhelpwin
xhelpdesk
xdemo
xver
*version
xwhatsnew
xReadme

Variables
*who
*whos
xworkspace
*clear
xpack
*load
*save
*quit

Functions
xwhat
*type
xedit
xopen
xlookfor
*which
xpcode
?inmem
who -functions
?mex
system(["mkoctfile ", name]);

Load path
*path
+addpath
Etienne Grossman
+rmpath
Etienne Grossman
xpathtool

User output
*echo
*more
*diary
*format

Environment
*cd
xcopyfile
*pwd
*dir
?delete
unlink
*getenv
*mkdir
?dos
+unixexecute unix command
Paul Kienzle by Laurent Mazet
?vms
Octave has only system; the advantage to having all three, with only one being functional in any given operating system, is that you can issue the equivalent commands for each operating system right after one another without having to check which operating system the script is running on. Note that matlab has the equivalent of system with the ! operator. Unfortunately, this cannot be implemented in Octave because ! is already used for negation.
xweb
*computer
computer, but returns different output for the same computer I bet

Debugging
?dbstop
trap-error from Paul Kienzle adds a stop_on_error flag; a modified version of this patch is available in the bleeding edge octave, with a different name for the flag.
xdbclear
xdbcont
xdbdown
xdbstack
xdbstatus
xdbstep
xdbtype
xdbup
xdbquit
xdbmex
xerrortraptrap/ignore errors

Profiling
xprofile
xflops

Demos and Tests. (No Matlab Equivalents)
Some routines herein have embedded demo and test code. The following non-Matlab routines support this.
+exampledisplay demonstration code embedded in the script
+demorun demonstration code embedded in the script
+testrun test code embedded in the script
+asserterror if two values are not equal, or nearly so
+prettyconverts a value to a string
+speed_testcompare results and speed of separate functions