G-Tool (G2L) is a web service that currently provides transliteration of single greek tokens to latin. Its aim is to make this possible in a flexible way by using choosable rulesets which implement spatial and temporal differences. It is developed by Fabian Körner (BBAW) and Gabriel Bodard (KCL) and hosted by the Berlin-Brandenburg Academy of Sciences and Humanities.
<result method="greekToLatin" ruleset="en19" token="Φιλόξενος">Philoxenus</result>
Fuller documentation at address above.