Railo tries to adhere the CFML standard as good as possible, Still there are some differences like missing tags and functions or a slightly different behavior. This page and the ones below should describe the incompatibilities.
The following Tags and Functions are not supported by Railo in its current Open Source version:
cfapplet, cfgrid*, cfreport, cftree, cfformitem, cfformgroup, cftextarea, cfexchange*, cfpresent*, cffeed, cfpod, cflayout*, cfmenu*, cfprint, cfreport*, cfslider, cfsprydataset, cftooltip, cfcalendar, cfpdfform, cfpdfformparam, cfpdfsubform, cfNTauthenticate
isDDX, isPDFFile, precisionEvaluate, getSOAP*, getGatewayHelper, sendGatewayMessage, getPrinterInfo, queryConvertForGrid, verifyClient, ajax*, dotNetToCFType
createObjec: no support for type corba and .NET
decrypt/encrypt: no support for arguments IVorSalt and iterations
rand: no support for "IBMSecureRandom" algorithm
xmlTransform: no support for argument parameters
If you find any others that are not listed above please do contact us so we can update our list as well as contact the Railo development team.