Zoji - As claimed by the developers of this Zoji, it caters online tools to aid you plan activities off-line.
EventBrite Online RSVP - EventBrite Online RSVP is a cost-effective event management software that provides services to help businesses organize, invite people together for an event, and sell tickets.
Pingg - Pingg is an online e-cards and invitation maker and invitation sending platform.
Rsvpify Virtual Events - Rsvpify Virtual Events is an event management tool that provides you various functionalities ranging from setting up the entire event to selling the tickets online to the targeted audience.
Manvite - As the name of this service suggests, the users can avail easily and simply invite rather than online summons that are blessed with flowery fonts and dabbling champagne glasses.
Whoozin.com - Free RSVP Online | Track RSVP’s and Sell Tickets for your events and recurring meetings.