Hi,
my two pennies' worth
If you are thinking of enterprise level applications i.e. banks and/or large IT corporations than:
- Java, Oracle (for middle-tier / back-end) and SOAP, XML Schema or Relax NG (for the data communication tier) will pretty much have you covered.
If you want to develop web-based applications than:
- PHP, MySQL (may be PostgreSQL) for the middle-tier/back-end and XHTML, AJAX (i.e. Javascript) and CSS2 for the eye candy
Finally, if you wanna go for low level unix programming for example than:
- C / C++ and PERL would not hurt
Cheers,
Mike