There is no such thing as a specific jumpseat pass like in the US, but accepting staff ticket holders for cabin or cockpit jumpseats is pretty common practice (nothing like one in the rear galley between Entebee & Brussels on a 2am flight...). Accepting someone to the cockpit is usually captain's discretion, some airlines are more accommodating in this regard than others, LH and SK in particular never left me behind if there was an available jumpseat anywhere on the plane. The only restriction is the UK where only authorised persons can be in the cockpit, so if you do get a cockpit seat to a flight there, over the channel you are asked to swap places with a flight attendant.
Free/reduced tickets are granted to own and other airlines staff (mostly on seat available basis), there are a number of multilateral agreements in place among network carriers, but low-costs are usually not party to these, they only grant reduced rate travel to own staff.