If you use Oracle XE for development, then you know it has a simple web interface through http://localhost:8080/apex. Now port 8080 is a common port used by Tomcat server, so letting Oracle XE permanently have taken it is not convenient. But you can change it like this:
sql> select dbms_xdb.gethttpport from dual;
sql> exec dbms_xdb.sethttpport('8081');
sql> commit;
bash> open http://localhost:8081/apex
Also, if you ever deleted the HR sample database on the XE installation, you can restore it like this:
bash> cd /c/oraclexe/app/oracle/product/10.2.0/server/demo/schema/human_resources
bash> sqlplus system < hr_main.sql
