QUESTION: Lectionary for Mass in Liturgy Layout

As others have noted, the Logos Catholic Lectionary resource is a tool that allows you to look up, read and study the readings for Mass in any translation you choose, but the Lectionary for Mass is the official text of the lectionary for use in the United States.

The official text is based on the New American Bible with Revised New Testament and Psalms (i.e. the NAB as it stood in the 1990s), but doesn't match it or any other translation exactly.

Changes were made from the NAB for a number of different reasons. Sometimes small changes were made for simple clarity as Don mentioned--most prominently, the official text often adds an brief "incipit" to provide necessary context explaining who's speaking, who's being addressed, etc. Sometimes, changes were made because of differences between the NAB's base texts and those of the Nova Vulgata--particularly in Sirach.

In some cases, changes were made because the Vatican was concerned that the translation of the revised NAB NT and Psalms obscures the meaning or traditional interpretations that are often the basis for selection in the lectionary. This is particularly the case with the inclusive language of the revised NAB Psalms. Many psalms are traditionally read (and paired with readings in the lectionary) as referring to Christ, but this may be obscured by the use of "they" instead of "he" in the NAB's revised Psalms. (E.g., NAB Psalm 1:1 has "Happy those who do not follow ...", while the Lectionary has "Blessed the man who follows not ...".)

Note too that that edition of the NAB is no longer sold. The 2011 New American Bible Revised Edition has a revised Old Testament (including re-revised Psalms), which means it differs even further from the official liturgical text.

Some other differences between the dynamic text Logos lectionary and the official Lectionary for Mass:

• The dynamic text feature used to pull text out of your Bible translation into the lectionary resource is only accurate to the verse level, so when a reading starts or stops in the middle of a verse (e.g. "15a", "30b"), you'll need to reference the official text to see the exact break point.
• The Psalm Responses and verses for the Alleluia and Lenten Gospel Acclamation are translated by ICEL rather than being taken from the NAB, so these will nearly always differ. In some cases, they're not taken from a Biblical text at all, so they can't be pulled into the dynamic text resource. (These are indicated by the word "Text" in the dynamic text resource.) The official text has to be referenced for these.
• For the Responsorial Psalms, the official text indicates when the response is to be said.
• The Lectionary for Mass includes the General Introduction to the Lectionary, which explains the principles behind the Liturgy of the Word and the Lectionary and how it is to be used.

So, in summary--the Logos Catholic Lectionary resource is a great tool for study and devotion, but it's not a replacement for the official text, particularly if you're preparing for the celebration of the liturgy.

Will this official Lectionary for Mass be the text used when clicking into the Liturgy Layout from the homepage?  (versus the current lectionary)

There are some technical things to figure out, but we're planning on making it possible to have the official text available from the homepage--both as an option for the text pulled dynamically into the Logos lectionary resource and opened behind this to the proper location as we do with the Roman Missal.