Apache OpenOffice and LibreOffice are the modern descendants of OpenOffice.org. For the last few years, almost all Linux distributions have included LibreOffice as their default office suite. However, in the past eighteen months, OpenOffice has reappeared, newly organized into an Apache project, and free software users now have the choice of two full-featured suites instead of one.
Users also have the difficulty of deciding between two almost-identical choices. The two diverged three years ago, and while that can be a long period in software development, in this case, the differences are only starting to become obvious. While considerable cleanup has gone on behind the scenes, the feature sets and underlying logic in both has mutated in only minor ways from the days of OpenOffice.org.
Here and there, you can find new features in the individual applications, especially in the Writer word processor. However, most of the differences are at a higher level, in support for formats and fonts, the policy towards extensions, and, most of all, in the efforts to modernize and standardize the interface.
Differences in the Apps
Most of the features in LibreOffice's and OpenOffice's applications are the same. In Draw, there appear to be no difference at all. In Impress, the main difference is that LibreOffice's latest release includes support for controlling a slide show from an Android device. And although the selection of slide backgrounds differs between the two, either selection should be adequate unless you are looking for a favorite. Similarly, the greatest difference between the two versions of the Calc spreadsheet is that, in LibreOffice's, you can create data forms.
Even in Writer, the most popular application, the differences are generally in a minor key. In LibreOffice, the status bar at the bottom of the editing window now includes a word and character count. In addition, LibreOffice's comments can be anchored to paragraphs rather than a single point, and, in a correction of a longstanding bug, in footnotes now display besides the text to which they refer. LibreOffice also adds a simplified Find field, similar to one in a web browser, while omitting the option to insert a graphical horizontal line -- a feature that few must have used for the last decade or more.
Formats and Fonts
Some of the more noticeable differences fall under the category of format and font support. For instance, OpenOffice continues to support saving to formats that have gone out of fashion, such as AportisDoc (Palm) and Pocket Word. It can open .docx files, but, unlike LibreOffice, not save to it.
LibreOffice also has the advantage in font support. The latest version supports OpenType, the preferred format for modern fonts because of its support for multiple languages and advanced typography. Even more importantly, by going to File -> Properties -> Fonts, you can embed fonts into the document, eliminating with a single click the need to ensure font compatibility.
Such features give LibreOffice a decided edge when exchanging files with Microsoft Office users. In general, neither OpenOffice nor LibreOffice interact best with Microsoft formats when a document is mostly text and contains a minimum of tables, draw objects, and complex formatting. In both, for example, you are best off sharing something like a brochure in .PDF format rather than the native Open Document Format.
However, if you do exchange native and Microsoft formats, LibreOffice has some decided advantages. Not only does it both read and write to recent Microsoft formats, but its advantages in font handling removes any need for font subsitution -- a major cause of problems when exchanging files. While other problems remain, such as differences in feature implementation, LibreOffice should generally be the more reliable handler of Microsoft Office files.
Both OpenOffice and LibreOffice support well-rounded collections of extensions that can be downloaded and added in minutes to enhance or alter features. In most cases, an extension that works with one will work with the other.
The difference is that, with LibreOffice, you don't have to install the most popular extensions. Instead, LibreOffice installs with them already enabled or integrated. These extensions include Lightproof, a basic grammar checker; Report Builder for summarizing and printing from data bases; Presentation Minimizer for reducing the size of presentations; Wiki Publisher for blogging, and Presentation Console for delivering slide shows, as well as a number of others.
All these extensions are available for OpenOffice as well. The difference is that, with OpenOffice, you need to know about them and deliberately find them. Effectively, this limitation makes a number of features unavailable to new users. When OpenOffice (and LibreOffice) have made such efforts in recent releases to provide useful modern templates and clip art, this omission is a crippling oversight, especially when it is so easily corrected.
Interfaces in Transition
In the twelve years that Sun Microsystems and Oracle have owned the OpenOffice.org code, the interface, like so many features, was almost entirely neglected. The result is that today, both OpenOffice and LibreOffice are suites with a healthy set of features, but interfaces that are generally stuck in the mid-1990s. Some superficial aspects have been removed, but far more remains to be updated.