Can I use Oracle Standard or Enterprise edition for my own training purposes?

Question is about Oracle licensing terms.

I would like to learn more about Oracle Database administration. Unfortunatelly I am using 32 bit verison of LInux, so I can't install Oracle 11 XE (I can't find 32-bit edition though).

Is it OK, if I download and install Oracle Standard or Entrprise on my personal notebook, and use it with no additional costs and hidden license issuses, is it even possible? I won't be using it for any commerce, even open-source project - I will only be using this installation to improve my DBA skills.