OpenLogViewer is a cross-platform data-log display program that currently supports MegaSquirt style CSV and FreeEMS binary data-log formats. It is currently in its infancy. While in the future it will be amazing, right now it has all of the basics that you need. For free. With no nag screens!
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OpenLogViewer, or OLV for short, is an open source project originally concieved by Bryan Harris. He says that he created it due to boredom, but that he intends for it to be reasonably easy to use. Ben Fenner, and to a lesser extent, Fred Cooke have done significant work to turn that dream into reality with UI and performance enhancements across the board.

Gufi, as Bryan is known to his friends, would love for the program to become mainstream in the Automotive Datalog area as a tool. We feel that it's well on its way to doing just that.

Where do I get it?

Download the latest release from the official OLV website or get the latest development version from the build server! . Until 0.0.3 is released, the development version is a far better choice.


Running a precompiled version

For using the precompiled application you only need a Java Runtime Environment (JRE) version 6 or above.

Building the latest from source

If you want to build the latest from source to make customisations, then you will need a Java Development Kit (JDK) version 6 or above AND maven 3. Maven 2 is not suitable as the project is configured for a number of plugins which are not compatible with maven 2. Additionally maven 2 does not provide the 100% stable build environment, which maven 3 does. Get maven from this link and follow the install instructions further down the page.

Additionally, you need to install the included settings.xml file in your ~/.m2 directory. This allows your build to include artifacts that are only available from the Maven repository.

You can get the source from one of the following repositories; use the network function to figure out whose is newest (though not necessarily best!): - Tested commits - Latest from Fred - Latest from Ben

A direct link to the network function:

Use git to obtain the source in an efficient way, for example:

git clone git://

Using Ant

Ant is deprecated in the professional development world, for good reasons, and as such is not supported as a build tool for this project.

Running OLV

To run an OLV jar in a graphical desktop environment such as Microsoft Windows Gnome, KDE, or Mac OS X, simply double click the jar file. To run it from the command line use the following command:

java -jar OLV.jar

Where "OLV.jar" is replaced with the name of the file that you downloaded.

If you're using Maven to build from source and run OLV, then the following simple command is all you need:

mvn -DskipTests

This does the same as "mvn install" and "mvn exec:exec" back to back. You may wish to clean the build directory before building and running, as you'd expect the required command is simply this:

mvn clean

Up to date documentation can be generated using maven in the following way:

mvn site:site

You can find the html index file in the target/site/ directory once complete.

OLV Website

If you don't want to build the latest from source then you can pick up the last release from the extremely basic OLV website below. Automatically generated documentation is available from the same site.

OLV Status

Currently the application has an excellent mouse-based navigation UI. Adding and associating fields with traces is still sub-par, but should be fixed soon.

The OLV development team are commited to regular releases of working software. This is the agile way, and as such have a clear roadmap for future releases.

Thanks for using this tool! We hope you love it as much as we do.

The OLV Team.