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Linguistic Tree Constructor

About LTC

LTC is a free program for building linguistic syntax trees from text.

The user points and clicks their way to a syntactic analysis.

LTC is intended for quickly producing syntactic analyses of large amounts of text (think 100,000-200,000 words, or more).

The program does no analysis on its own. The user is completely free to draw the tree however he or she wishes. However, the program makes sure that the tree is a tree and not some other kind of graph.

Syntactic theories supported

Three "flavors" of trees are supported:

  • "Generic" syntax trees,
  • X-Bar syntax trees
  • RRG (Role and Reference Grammar) syntax trees (the LSC and the LSNP)

Labeling of nodes

The program supports adding "labels" to nodes. These labels are userdefinable, and can be used for such things as:

  • Subject-Object-Predicate analyses
  • Rhetorical Structure Theory analyses
  • Other discourse-level analyses
  • RRG operator-projection analyses
  • etc.


  • Draw syntax trees using point-and-click
  • Supports the following linguistic levels:
    • Word
    • Phrase
    • Arbitrary, user-defined levels...
    • RRG
    • XBar
    • Text
  • Phrase-level categories are user-definable
  • Both horizontal tree views and vertical tree views are supported
  • Both tree-view and brackets-view are supported
  • Supports up to five interlinear lines at word-level
  • Interlinear lines can be switched on and off individually
  • Change colors of individual parts of the display
  • Switch bracketing on and off for constituent levels
  • Change magnification
  • Unlimited undo
  • Copy (parts of) tree to clipboard as bitmap
  • Copy to clipboard in high resolution for publication-quality tree diagrams.
  • Printing
  • Uses any font (including Unicode fonts)
  • Supports right-to-left languages as well as left-to-right
  • Import from straight text (plain text)
  • Import from word-per-record SFM interlinear text
  • ... and many more ...

Platforms supported

LTC runs and is supported on the following platforms:

  • Windows / Win32 (Vista, 7, 8, 8.1, and 10)
  • Mac OS X (10.8, 10.9, 10.10, 10.11)
  • Linux

However, it should run on most POSIX-compliant *nixes, including Solaris.

As of version 3.0.0, Windows 95, 98, 98SE and ME are not supported.


LTC uses wxWidgets to write the GUI front-end.

LTC uses Emdros. Emdros is a text database engine, also called a corpus query system.

Who is behind this?

The author's name is Ulrik Sandborg-Petersen.