the install path in ubuntu is:
/usr/lib/oracle/xe/app/oracle/product/10.2.0/server

to open a web console: http://127.0.0.1:8080/apex

i had problems getting the sql script editor to work for a while. i was convinced i was missing some key configuration because all i would get is a non-working red screen. it turns out the sql script editor just flat-out does not work in newer versions of firefox and chrome. it works fine when accessed from IE7 from windows though.

i’d like to try installing 11g but it looks like the linux version is 64-bit only.