Twigs is as a free web service. It uses the same GEDCOM Parser that is used by VGedX Online, my 100% compatible GEDCOM validator. Twigs, however, supports a special expanded GEDCOM dictionary that will recognize numerous vendor specific events and date formats.
Your Twig once built, will be hosted by this site until such time as you delete it. Whenever you visit this page you will see a link to your Twig, and another to your latest Twig's build report. Your Twig will also be listed in the @Twigs section of the sidebar. @Twigs includes the 10 most recent Twigs built. These Twigs have the added benefit of being periodically updated to include the latest features, bug fixes, and style changes. Each time you update your Twig, it will be returned to the top of the @Twigs list. The most active participants' Twigs should remain in the list. I expect soon to create a new page listing all the current Twigs.
Twigs differ from Trees because they enforce hiding living data and privatization rules. They also force estimating birthdates, which are critical to determining accurately whether or not a person is likely to be still living. Twigs also lets you optionally add a Comments tab to (almost) every page in your Twig. Your visitors can easily leave you a comment to provide feedback which is a great way to get people involved in your research. When enabled, a Recents Comments menu item is also added to your navigation bar so that you can view your visitors' comments in one central location. Its also a great way for you to add a quick note or link to a profile page. All Twigs also have a Contact page automatically attached to their navigation bar so that visitors can send them an email message directly. These emails are currently coming from my email address, email@example.com so make sure they don't end up in your spam folder. Your email address is never published. Before anyone can post a comment or send you a message, they have to get through my security checking which seems effective. I have been using my commenting system for about 5 years and have only received 2 spam emails so far, though I do get hundreds of spambot rejects every day. I plan to extend some of the commenting features in the future such as letting you delete old comments that no longer apply and ban ips.