Name commonly used for the earliest handbook of church order: a collection of ethical, liturgical, social & eschatological instruction.  The work is known from a single surviving ms. transcribed in 1056, which was discovered in the library of the Jerusalem patriarchate in 1873.  The full title of this text is "Teaching of the Lord to the Gentiles through the Twelve Apostles." 

Claim of apostolic authorship apparently gave the Didache wide influence in early Greek churches.  Clement of Alexandria (2nd c. CE) & later Egyptian Christian writers cited portions of it as scripture.  In the 4th c. CE, however, its status became ambiguous.  Although it was accepted as an apostolic source by the anonymous Syrian scribe who compiled the compendium of ancient church orders called the "Apostolic Constitutions," Eusebius of Caesarea (4th c. CE) put it among the NT apocrypha.  Today it is often grouped with the "apostolic fathers": orthodox Christian writings from before 160 CE.

The Didache's contents indicate that it was probably composed by a Hellenized Jewish Christian in late 1st c. or early 2nd c. Syria.  Although its liturgical instructions are specifically Christian -- calling for baptism "in the name of the Father, Son & Holy Spirit" (ch. 7) & mention of "Jesus Christ" at the end of the eucharistic prayer (ch. 9) -- its ethical teaching (ch. 1-6) is generally Jewish.  Jesus' name is explicitly mentioned only in the prayers during & after the eucharistic meal, where he is regularly identified as just God's "servant."  Paradoxically, elsewhere he is referred to as "the Lord." Readers are instructed to gather for a thanksgiving meal on "the Lord's day" (ch. 14).  Yet there is no explicit commemoration of either Jesus' death or resurrection.

The Didache instructs people to pray "as the Lord commanded in his gospel" (ch. 8); & its version of the "Lord's" prayer is almost identical with the wording in Matthew.  Yet elsewhere it is not at all clear whether the Didache follows any gospel text or rather was composed from oral tradition similar to that used by the synoptic authors.  For example, the author cites the negative formulation of the golden rule commonly invoked in Jewish texts -- "do not do to another what you would not want done to you" -- rather than the positive formula from Jesus' sermon in Matthew & Luke. 

The view of church order presupposed by the Didache is communal & rather primitive.  While congregations are authorized to appoint "bishops & deacons" for themselves (ch. 15), these are introduced simply as substitutes for prophets & teachers in places where these are not available. Yet the Didache itself clearly addresses a situation in which wandering charismatic apostles, prophets, & teachers are not only a reality but a potential social problem for any community.  For the author devotes three chapters (11-13) to instructions on distinguishing true prophets from charlatans.

Although some scholars date the Didache after 100 CE, its contents converge to indicate that it was composed before the authority of bishops & the synoptic gospels had become well established. Its urgent conclusion, alerting readers to the imminent appearance of "the Lord," also stamps it as a product of the eschatological milieu of several NT works (e.g., 1 Thess, Mark & Revelation) rather than the doctrinal battles & power struggles of 2nd c. churches.

Other on-line resources:

• Full text of the Didache (posted by New Advent).

• Didache ton Dodeka Apostolon - Kirsopp Lake's 1913 transcription of the Greek text of the Didache from the Apostolic Fathers volume of the Loeb Classical Library (archived by Christian Classics Ethereal Library).

• Didache - Peter Kirby gathers extensive excerpts of scholarship on the Didache and links to all on-line editions of the text (Early Christian Writings).