Online-RSVP.com - Beautiful online RSVP for wedding & other events. Create an online invitation, track your guests responses.
Punchbowl - A party planning and greeting card website
RSVPify - A powerful and awesomely customizable platform for selling tickets online for your event.
BeingSo - Send free animated greeting cards, birthday invitations.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Meetinch Attend - Your personal RSVP tracking assistant