The word 'ily', is the shortened version of 'I love you', and is often used in texts, instant messengers, and in comment boxes on personal webpages.
Ily is usually read/said as all one word rather than pronounced as single letters such as 'I-L-Y'.
It is usually recieved as an affectionate term used more to describe your admiration for someone, rather than actual love, although can mean different things in different situations.
Boyfriend to Girlfriend: "Don't ever let me lose you, ily"
Friend to friend: "Ily girl!'
Texts: "Meet me by the cinema at 2 o'clock, ily, Fred"
Instant messenger: "Sorry, I g2g now, ily xxx"
Comment boxes: "What a pretty girl, ily!"