In the past few years I've read numerous debates on the topic of whether one should have one's genealogical tree available to others as a public tree, or hidden away (discoverable only in the sense that it exists but one does not share the details in a public manner) as a private tree.
As with many debates, it is not either/or, since one can have both. This would make sense if one considers the public tree to represent research work that you feel is sufficiently sourced and argued, while the private tree represents a work in progress that is not quite ready for prime time. In any event, this posting, and the related postings that will follow, are not really about that particular debate. If anything, these postings will be about a very different debate, namely, the experience of having a personal tree (a standalone tree that either you alone can edit, or only a limited number of people chosen by you can edit), or of participating in a unified tree (a single, shared tree that can be edited by anyone in the world, much like a typical wiki).
Before it became reality, I made some predictions on the Genealogy Guys Podcast that it was only a matter of time before we saw a company link its online trees (providing access to others) with desktop-based software (personal editing). Ancestry.com was in a position to do this since it had both its website for hosting trees and its Family Tree Maker software for desktop editing. In 2013, FamilySearch certified a number of software programs for synchronizing data with the tree on FamilySearch, including one that I was already using, RootsMagic (on a Mac under CrossOver). MyHeritage is now offering this via a sync to its Family Tree Builder software. [Note: Is anyone successfully running Family Tree Builder under CrossOver?]
In addition to the personal trees on Ancestry.com and MyHeritage, and the unified tree on FamilySearch, there are other sites that provide for unified trees. Geni.com (owned by MyHeritage since November 2012) provides such a tree, so there you have an example of a company providing both options. WeRelate (at werelate.org) hosts a unified tree using a wiki model, as does WikiTree (at wikitree.com).
Which brings us to the experiment: What would happen if I began to enter my direct ancestral lines, fully sourced, into each online tree? Who (if anyone) would contact me? Whose other trees would I encounter in the unified model, and how would we resolve conflicts? And how can I actually do this experiment in an orderly fashion so that it doesn't get too crazy?