Launching a comparison
Use the Document / Comparsion/Merge / New Text File Comparison (Ctrl+L) command to open an empty Text Comparison view or Document / Comparsion/Merge / New Comparison... (Ctrl+N) menu item to select the sources files to use and/or the options to apply to the new document. The dialog box allows you to open side-by-side or 3 way comparisons. You can check the Merge option to start with the merge pane open.
Additionaly, you can use the Document / Comparsion/Merge / Open conflict file menu item and select a conflict file generated by CVS, SVN, Mercurial, Bazaar, Git or Perforce. ECMerge will parse the markers or files stored aside the selected file and open a two or three-way merge with the appropriate content for the conflict resolution. ECMerge understands its own two and three-way merge textual markers so that you can open within ECMerge a file that you previously saved while partially solved (clicking 'yes' when you are asked to save including the text from all the sides mixed).
Working with comparisons and merges
Each source file is open as read-only and remain constant during the comparison or the merge. The merge result file on the contrary is produced by the process, it can be updated by hand as well.
The differences are presented by using different background colours for the modified lines. The modified lines are either added, removed, ignored or changed. You can define the colours in the Options dialog box. The current choice of colors is displayed aside basic statistics in the status bar. Within changed lines, character and/or word level analysis will show extremely valuable information by noting the only portions that were actually modified. It allows you to quickly find small modifications inside long lines of text.
Conflicts are displayed only in merge mode. When comparing two files, all the differences are as well conflicts. When comparing three files, Ellié Computing Merge can deduce in many situations what changed since the ancestor file was last modified. When the differences between the left and right files with the ancestor concerns related portions of the ancestor. The software cannot decide what to do, it defines a conflict so that your attention is attracted to the given portion of the file. The Resolving conflicts section explain features to solve conflicts.
Ignoring unimportant changes
It is often necessary when comparing or merging documents to ignore unimportant changes. There are two contexts to define those unimportant changes: file types and comparison options. In file types, you usually define comments as being ignorable in particular those containing source code control auto-generated information (change log, time stamp...). In comparison options, you choose whether you want to ignore indentation at start of lines, trailing spaces and if those ignorable lines are indeed ignored.
Comparing complex text formats (RTF, MS Word, OO Writer...)
Ellié Computing Merge can compare those files with the built-in converter Xtract, select the files normally they should show as simple text. ECMerge prevents saving over converted files and will request another path if you decide to change something then save.