It is common practice that IXPs offer various services to their peers (possibly behind a separate AS Number).
Services like NTP, Route Servers, Top Level Domain DNS Servers and DNS-Root-Servers are typical services that can but do not have to be offered to the IXP community. This is usually done in a separate AS-Number, so that the services behave like an IXP customer of its own.
Additionally, services that humans can interact with are commonly offered to the IXP Members. Looking Glass services provide an interactive view on the routing-tables from a peering router. Furthermore many IXPs offer various forms of statistics, these may contain port traffic graphs, peering traffic views, peering matrices, etc. The website usually informs about connection policies, pricing, and much more. There is a separate IXP Website BCOP concerning this.