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22:29, 22nd September 2017

Frequently asked Questions

Q: Is Lx-Viewer a GPL product?

A: Lx-Viewer is distributed under a modified version of the GPL license. The code we have written is free, but because the compiled program links to a non-free library (the OpenDWG libraries) we have to put a small amendment on the GPL license, which is then a modified version of the GPL license. The ammendment is in exact accordance with the FSF Guidelines.

The full text of the Lx-Viewer license may be viewed online as a text file or html file.

Take care to review the OpenDWG terms as you will be bound to agree by these in order to download the libraries. Be sure to fill in one of their PDF terms and conditions and post it back to them as otherwise they will have difficulty proving you have a legally binding agreement with them.

To summarise briefly: Under the OpenDWG library terms, you are only allowed to use the compiled Lx_Viewer for personal use and internal comapny use, e.g. you can't sell it with the OpenDWG libraries. The limitation on commercial use applies only to selling a program based on the libraries. You can sell our source and have the users download the libraries and compile seperately. You can also distribute compiled versions of the program as long as they are without fees. If you want to sell compiled programs using the OpenDWG libraries though, you need to buy the appropriate license from the OpenDWG alliance.

Q: The restrictions on the OpenDWG libraries suck!

Yep. Too Right. But if you think this sucks, please write a GPL/LGPL library that allows manipulation of DWG files, or help someone who is doing so. We don't like the OpenDWG license, but it's all there is currently. Flames won't help anyone. Find a manically good coder and tell him about the injustice of not having a decent GPL CAD library.

Q: Do I need additional files from the OpenDWG Alliance?

A: That depends. If you plan to compile the program from the source files then the answer is yes. You will need the files ad2.a and ad3.a for Linux which are available from the OpenDWG alliance. It will be necessary for you to become a member of the alliance, but membership is free so long as you are using the files for personal use or for use internally within your own company. After you download these files copy or move ad2.a and ad3.a into the subdirectory OpenDWG which should be created when you expand the Lx-Viewer tar.gz archive.

When you download the libraries from OpenDWG there will be lots of header files plus examples included. Do not use any of the header files with LX-Viewer. We supply our own versions, many of which have the same names as the OpenDWG header files, but with different content.

If you are using a precompiled version of Lx-Viewer then no additional files are necessary since the two files above are static linked into the program. eg Windows users and RPM users, you get a compiled binary so you don't have to worry about this.

Q: What dependancies are there? / What version of QT do I need?

A: For all recent versions (after v0.96) you needed QT 3.0.5 or better. QT3.0.3 will not do and will give you errors. If you compile the Lx-Viewer sources your self you will need the QT headers etc which, on an RPM based system, will be included in the Qt-devel RPM. If you only need to run the precompiled version then it is sufficient to just have the QT runtime libraries installed on your computer.

If you are using an old distribution with QT 2.x then we recommend using the old 0.96 release.

You will also need a compiler at least as new as the one the OpenDWG technicians have used to compile the OpenDWG libs with. The newer versions of GCC will do fine, such as GCC v3.2 or better.

Q: I'm compiling and I get a "Qt not found" error

A: This probably means you have QT installed but that your system hasn't been told where it is. This is easy to fix:

Check out the install guides and the forums (see the Lx-Viewer-Mandrake 9.1 install guide even if you aren't running Mandrake) concerning specifing the paths to your Qt libs.

Q: I'm using the experimental version and I'm getting an error

A: Check the forums to see if someone's asked the same question, if not we want to hear from you and we'll fix the problem.

Page last modified: 1 January 1970 00:00