I think you're thinking of Opera Mini, which was a (set of?) thin client(s) that ran on feature phones and rendered a proprietary lightweight binary transport (OBML) that those phones could handled. OBML was generated on a proxy server running a fully featured web rendering engine (which may have been Presto).
Opera's Presto engine was mainly used in their desktop and smartphone browsers. It was not used directly in Opera mini on feature phones.
> Raise of cheap full featured ARM CPUs made it obsolete.
Not sure what this means. How would ARM make a browser obsolete?
ARM Made opera mini obsolete because there were no more users. The people that have a phone it runs on don’t want a browser or they’d get a smartphone, the people with a smartphone don’t want it because they can use a real browser
Opera's Presto engine was mainly used in their desktop and smartphone browsers. It was not used directly in Opera mini on feature phones.
> Raise of cheap full featured ARM CPUs made it obsolete.
Not sure what this means. How would ARM make a browser obsolete?