I have seen their website and all that. But what exactly are they?

Got a quick pass through it's services -- looks like a banking and trading exchange service, but to ensure that your connection's secure you need their add-on for firefox ( Liberty Guard ) -- unlike Paypal that goes automatically HTTPS on this main page; also checked the comparison rate charts -- need options about it, I'm stumped over it too

Is it recommendable?

LibertyReserve is a payment processor and been operating online for many years.
I don't like them, but some people do and it's another payment option here.