Something I’ve found out this morning; If you want to include localized resourced in your project other then en_US, for instance nl_NL, you not only have to create resource files for your own application, but you also need to provide the localized resources for the Flex Framework components. Flex doesn’t have all these localized resources out of the box, but Adobe provides a command line tool to copy these resources. It’s called copylocale.

Now I’m not frequent user of the command line, but I know terminal (on my mac) a bit, so I just navigated to the bin directory of my Flex sdk and did this:

copylocale en_US nl_NL

Didn’t work. Terminal just sais:

-bash: copylocale: command not found

Turns out you have to call the copylocale command from the root directory of your sdk, and include the /bin in the command call, like this:

bin/copylocale en_US nl_NL

Damn command line tools, no one ever tells you this stuff.

Some more info on runtime localisation:
http://labs.adobe.com/wiki/index.php/Flex_3:Feature_Introductions:_Runtime_Localization