The Open Siddur is an online tool for individuals and groups to craft the siddur they’ve always wanted. The Open Siddur will provide content (translations, transliterations, art, tfillot, piyutim, and other source texts) from an archive of current and historic nusḥaot (both well-known and obscure) and enable users to adapt, contribute new content, and share the siddurim they’ve generated. Partnerships with on-demand printers enable users to print beautiful copies of their personally customized siddurim and machzorim. The Open Siddur benefits independent minyanim and trans-denominational communities, pluralistic institutions, teachers of Jewish liturgy, and Jews of all ages evolving their personal use of t’fillah in their own daily practice, both alone and within groups.