Here is a list of CRPL commands. Current as of February 2nd 2014. If it is red in this list, it is not documented.

Command
abortmove
abs
acos
add
addadditionalscore
addconversationmessage
addcreeper
addscripttounit
and
appendstacktolist
appendtolist
approximately
artifactcollected
ascendtoorbit
asfloat
asin
asint
atan
atan2
break
ceil
celltopixel
clearconversation
clearlocals
clearqueuedmoves
clearstack
cleartracelog
concat
conversationshowing
copylist
cos
createeffect
createeffectclipped
createindicatorarrow
createlist
createliststartingsize
createmist
createrunner
createspore
createunit
currentcoords
currentpixelcoords
currentx
currenty
damage
damagecreeper
deepcopylist
delay
destroy
destroyallenemyunits
destroyconversation
destroyindicatorarrow
disabletowerfield
distance
div
do
dropfromorbit
dup
dup2
e
elapsedtime
else
enablealternatecontrolmode
enablenormalkeyinput
enablenormalmouse
enabletowerfield
endif
endonce
endswith
endwhile
eq
eq0
failmission
false
fireaoo
floodfillterrain
floor
getadditionalscore
getallunitsinrange
getcameraposition
getcelloccupiedcount
getcommandnodecount
getcoreswithvar
getcreeper
getcreepercolors
getcurrentbuildtab
getdeepestcreepercell
getdigitalis
getdigitalisgrowth
getdigitalisraw
getenemyunitsinrange
getfieldcell
getgametimeframes
getglobalrunnercount
getimagecolor
getimageposition
getimagepositionx
getimagepositiony
getimagepositionz
getimagerotation
getimagescale
getimagescalex
getimagescaley
getkey
getkeydown
getkeyup
getlistcount
getlistelement
getmousebutton
getmousebuttondown
getmousebuttonup
getmousecell
getmouseposition
getmousescreenpixelposition
getmousescreenposition
getnearestgroundenemy
getpinfieldcell
getqueuedmovecount
getrunnercount
getscore
getscriptvar
gettargetoffsetx
gettargetoffsety
gettechartifacttype
gettechlimit
getterrain
getterrainoverride
gettimer0
gettimer1
gettimer2
gettimer3
getunitat
getunitattribute
getunitcountinrange
getunitsinrange
getunittargetoffsetx
getunittargetoffsety
getunittransformposition
getunittype
getupdatecount
getvoid
getwall
gt
gte
hidetracelog
i
if
insertlistelement
invocationcount
iscreeperinrange
isdigitalisconnected
iseditmode
ismessagedialogshowing
ispaused
isterrainlos
j
k
ln
log
log10
loop
lt
lte
makerain
mapheight
mapwidth
max
min
mod
mul
neg
neq
neq0
not
notpersist
once
operatewhilepaused
or
pathfindterrain
pausegame
pi
pixeltocell
playsound
pop
pow
prependstacktolist
prependtolist
queuemove
randcoords
randcoordsinrange
randfloat
randint
randunitcoords
randxcoord
randycoord
removeimages
removelistelement
repeat
resetgametime
return
round
screenheight
screenwidth
self
setadditionalscore
setanticreepermax
setbuildlimit
setcameraposition
setcelloccupiedcount
setcreeper
setcreepercolors
setcreeperevaporationlimit
setcreeperflowrate
setcreeperflowrateondigitalis
setcreeperflowrateondigitalisrl
setcreeperflowrateondigitalisud
setcreeperflowraterl
setcreeperflowrateud
setcreepermax
setcreepernolower
setcurrentcoords
setcurrentx
setcurrenty
setdigitalis
setdigitalisgrowth
setdigitalisraw
setfieldcell
setgametime
setgametimeframes
setimage
setimagecolor
setimageposition
setimagepositionx
setimagepositiony
setimagepositionz
setimagerotation
setimagescale
setimagescalex
setimagescaley
setlistelement
setpinfieldcell
setpopuptext
setpopuptextalwaysvisible
setpopuptextx
setpopuptexty
setscreencoords
setscreencoordx
setscreencoordy
setscreenmode
setscreenpixelcoords
setscreenpixelcoordx
setscreenpixelcoordy
setscriptvar
setsysteminhibited
settargetoffsetx
settargetoffsety
settechartifacttype
settechlimit
setterrain
setterrainoverride
settext
settextanchor
settextcolor
settextsize
settextx
settexty
settimer0
settimer1
settimer2
settimer3
setunitattribute
setunittargetoffsetx
setunittargetoffsety
setvoid
setwall
setwind
shortestangle
showconversation
showmessage
showmessagedialog
showmessagedismissible
showopeningconversation
showtracelog
sin
split
sqrt
stacksize
startswith
stringlength
stringtolist
sub
substring
suspendmove
swap
tan
tolower
toupper
trace
trace2
trace3
trace4
trace5
tracestack
true
unpausegame
wasmessagedismissed
while
xor