This is a slightly more comprehensive summary of what vodle is than in the README. More details can be found by following the links to individual glossary entries throughout this text.
Vodle is a web-app (later also a smartphone app) that lets a user (the "initiator") set up a ["poll"]](documentation/development/GLOSSARY.md#poll) stating a collective decision problem such as choosing a single option out of a number of options, choosing a fixed number of candidates from a list of candidates, distributing a budget of some sort (monetary, time, space, other resources) among a list of projects, etc. The initiator can then invite a selected group of ["participants"](](documentation/development/GLOSSARY.md#participant) (or the general public) to participate in the poll by sending them an email containing an invitation link or direct message containing a deep link to the poll. The invited participants can then take part in an interactive, consensus-oriented decision process until the set deadline at which the poll will end. Once the poll ends, the results are determined by a certain tallying algorithm that was optimized for fairness and for giving participants incentives to find a good compromise and choose that compromise as a full or as-broad-as-possible consensus.
That social choice algorithm (published in this theoretical paper) is based on the idea that participants may conditionally commit to approve an option if enough other participants do so as well. To this end, each participant can give each option a "wap" (willingness to approve) between 0 and 100, where 0 means "don't approve", 100 means "approve for sure", and 1..99 means "approve conditionally". More precisely, a wap of X means the participant will approve iff strictly less than X% of all participants do not approve. The rationale for this mechanism is that this gives participants an incentive to approve good compromise options without risking that participants with opposing preferences exploit this cooperative behaviour (somewhat similar to a prisoners dilemma). (Rational participants can be proven to thus converge to a consensus.) A central feature is that participants can see the development of support for all options in real time in an aggregate, anonymized way, and can react to it by adding promising compromise options and adjusting their waps at any time before the deadline.
Once the poll ends, everyone's waps are turned into approvals, and based on these every option gets a "share" of the budget or of the overall winning probability. The share of an option equals the proportion of participants that approve that option but approve no other option that received more overall approval. In other words, each participant can be seen to "control" an equal share, which goes to the most popular option among those approved by that participant. This way, the mechanism gives all groups, whether in a majority or a minority, control over a fair share of the winning probability or budget, rather than concentrating all power on a (possibly very slight) majority.
Another central feature is that participants may delegate their specification of a wap for all or a selected number of options to some other participant that they trust and whose waps would then also count as the waps of the delegating participant, in a way similar to the concept of Liquid Democracy.
All data processing and tallying logics are implemented in the local front-end (browser or phone), the only central server component is a freely selectable public database (CouchDB) used for exchanging end-to-end encrypted data between the participants.
While many aspects of vodle are similar to d**dle, the main focus of vodle is not to collect data about preferences but to actually arrive at a collective decision in a transparent, privacy-preserving, and consensus-oriented way.