Visifire is a very good graphing component for making silverlight or WPF applications.  The component was first released as an open source library on GoogleCode, but since then has been made a closed source proprietary and for profit project.  The newer version contains several enhancements, but the open source version is still quite useful.  The greatest advantage is that while chart rendering can be impossibly slow with the Silverlight/WPF toolkit, it is very fast with visifire.

Unfortunately, it is hard to find the original open source version, it is available at: https://code.google.com/p/visifire/ .  Even after downloading the open source version, one still sees a rather annoying “Visifire Trial Edition” banner in the upper right corner (shown below), which looks unprofessional.

Removing this in the source code is complicated because this “Trial Edition Tag” is generated in an obfuscated fashion (presumably to prevent people from doing just that).  The text and hyperlink are encoded as byte arrays, which are unpacked in a somewhat convoluted way.  They can be found in the Visifire Control class.

private static Byte[] wmRegVal = new Byte[] { 0x56, 0x69, 0x73, 0x69, 0x66, 0x69, 0x72, 0x65, 0x20, 0x54, 0x72, 0x69, 0x61, 0x6C, 0x20, 0x45, 0x64, 0x69, 0x74, 0x69, 0x6F, 0x6E };

private Byte[] wmLinkVal = new Byte[] { 0x68, 0x74, 0x74, 0x70, 0x3A, 0x2F, 0x2F, 0x77, 0x77, 0x77, 0x2E, 0x56, 0x69, 0x73, 0x69, 0x66, 0x69, 0x72, 0x65, 0x2E, 0x63, 0x6F, 0x6D, 0x2F, 0x6C, 0x69, 0x63, 0x65, 0x6E, 0x73, 0x65, 0x2E, 0x70, 0x68, 0x70 };

After downloading the open source version, simply search for these arrays, comment them out, and then comment out the one line that uses them them when directed to by the compiler error.  Rebuild, and voila!  No more banner in your open source software.