After I installed the Rapid Configuration Tool with AX2009, the installation went successful and I was able to see a separate RCT module being added in AX client along with other modules. But when I navigated to the module, I only saw label ids (@RCT) for menu items, forms etc. As per the given guidance in ReadMe document, I restarted the AOS but things did not work for me. My machine locale was set to US. Further investigation revealed that axRCTen-us.ald and other relevant files in C:\Program Files\Microsoft Dynamics AX\50\Application\Appl\DynamicsAx1 were missing.
The workaround I did then was to stop the AOS, copy and paste the axRCTen-gb.ald, axRCTen-gb.alc, axRCTen-gb.ali files in the same folder, rename the copied files by replacing 'gb' with 'us', start the AOS, open up AX client and now the proper lable text were there in RCT module.