Commercial Use

[grimtar27]

I scoured the website for calibre, as well as the user manual, and even searched mobileread. If it's in one of those, I apologize.

I'm interested in using calibre's conversion capabilities to provide the document reformatting for a work in progress ebook website. ( I can't go into too much detail, as it's still in the business plan/startup phase.)

I can't seem to find the license calibre is developed under. I'd love to use it, but obviously have no intention of it unless I can get confirmation it's legal. From what I can gather on the forums it's fine to use it for whatever personal use, but I dare not venture into the commercial realm without a go ahead.

It will take some heavy adapting, but a large amount of the conversion legwork is done for me, which is why I'm so interested in using it, I'd be more than happy to make a nice donation, or whatever would be required of me for using it in a commerical purpose.

On another note, if a commerical use is indeed permitted, I'd love to find someone heavily familiar with calibre who'd like to help me adapt it, ( I'd be fine with paying them too for their work, I'm not trying to be a cheapskate here.)

If it's not at all, then I understand and will not attempt any underhanded dealings, I'll get to work on designing and implementing a solution from the ground up.

Thanks in advance for anyone who has any answers.

Tyler.

[theducks]

Originally Posted by grimtar27

I scoured the website for calibre, as well as the user manual, and even searched mobileread. If it's in one of those, I apologize.

I'm interested in using calibre's conversion capabilities to provide the document reformatting for a work in progress ebook website. ( I can't go into too much detail, as it's still in the business plan/startup phase.)

I can't seem to find the license calibre is developed under. I'd love to use it, but obviously have no intention of it unless I can get confirmation it's legal. From what I can gather on the forums it's fine to use it for whatever personal use, but I dare not venture into the commercial realm without a go ahead.

It will take some heavy adapting, but a large amount of the conversion legwork is done for me, which is why I'm so interested in using it, I'd be more than happy to make a nice donation, or whatever would be required of me for using it in a commerical purpose.

On another note, if a commerical use is indeed permitted, I'd love to find someone heavily familiar with calibre who'd like to help me adapt it, ( I'd be fine with paying them too for their work, I'm not trying to be a cheapskate here.)

If it's not at all, then I understand and will not attempt any underhanded dealings, I'll get to work on designing and implementing a solution from the ground up.

Thanks in advance for anyone who has any answers.

Tyler.

Moderator Notice
This section is for Developers working on new code per the sticky.
Moving ...

Calibre is licensed under GPL. Free otherwise (donations accepted)

[DoctorOhh]

Originally Posted by grimtar27

II can't seem to find the license calibre is developed under.

Read the file named LICENSE in calibre's program directory.

[user_none]

The GPL v3 license calibre is licensed under does not restrict use. The short summary of what the GPL says is if you distribute calibre (with any modifications) you must make those modification available to anyone receiving your modified version and the changes must be licensed under a compatibile license (typically the GPL v3 that the orignal is licensed under).

Also, there are a number of commercial entities using calibre as part of their ebook conversion process. Comercial use if fine as long as if you decide to or start distributing a modified version of calibre you comply with the terms of the GPL that calibre is licensed under.

[garylisbon]

Hi,

Thought to inquire under the same thread as it relates to a commercial situation. Forgive me for my question, a newbie dev here without any experience in licensing.

I'm currently working for a software company and I'm in a team that is developing a website for a public library and developing a custom ebook viewer to view the ebooks. Rather than writing code to support epub, i thought of converting epub to pdf instead to reduce the effort spent.

Since calibre is under GPL v3, i am quite confused on whether i can use calibre in our application. Basically we have a custom ebook viewer embedded on the library site. We have a server that will stream the pdf output to the viewer. We would be using Java in the server side(a servlet) hosted via tomcat and will be calling calibre via runtime through command line options. Calibre-windows will be installed in the server located at the library by us. I don't think our server code will be licensed under gpl unfortunately. Calibre will be used for purely for server side conversions. No modification of calibre will take place. The pdf output will be the one that will be streamed to the viewer.

Java snippet:
Runtime.getRuntime().exec("ebook-convert... <command-line here>");

Would this be permissible? (Am confused on legalities of the gpl especially the aggregates and derived works so I wanted to ask here first before we get into a legal mess/also read a little about what happened to hamstersoft) are there any steps that we must do instead of the above? (i.e the users/client should be the one to install calibre on the server, etc)

Tried to look for commercial alternatives but so far only calibre meets our expectations.

Sorry the long post and thanks,
Gary Lisbon

[user_none]

@gary,

If you distibute calibre in binary form you must also distribute it in source form to anyone receiving the binary version. This includes any modifications you have made to it.

If you use source code from calibre in another application you must license the program in a way that is compatible with the GPL v3.

If you use calibre as the basis for another application and calibre is a substantial portion of the other application then the GPL requirements apply and your application would be considered a derivative work. If you can say no to these questions your application is not considered derivative. Do you use any source code from calibre? Are you distributing calibre? Most important, does your application require calibre to work?

From what you described it sounds like you are fine. As long as calibre is a small part of the functionality of the application. The user installs calibre there self and your application will use it if available. The application calls calibre using system calls not linking to it. Also if your application is structured in a way that you can use multiple different conversion programs you are fine. Your best bet is to do what you're doing and keep calibre separate and working at arms length from your application. User installed and not linking will keep you in compliance.

In the case of the ebay listing, if the person includes calibre's source code on the dvd then they're fine as far as calibre is concerned.

[garylisbon]

Hi,

thanks for the quick reply. Just a few clarifs.

Originally Posted by user_none

The user installs calibre there self and your application will use it if available.

Can we install calibre ourselves though we will inform the users that we will install the software ourselves on their server as part of the installation procedure? (Just asking, since it would be better to use calibre at the start to avoid quality problems in the other conversion products that will result in bug reports)

Originally Posted by user_none

As long as calibre is a small part of the functionality of the application.

Yes, it will just be part of converting the epubs that will uploaded to pdfs with a batch job. our app consists of other functions like viewing videos, booking, reservation and other library functions.

Originally Posted by user_none

The application calls calibre using system calls not linking to it.

Just to be clear, calling ebook-convert from a java command (Runtime.exec) that executes command line arguments is not considered as linking right? (Not sure of the scope of the term linking in the license)



Thanks again.
Gary Lisbon

[user_none]

Originally Posted by garylisbon

Can we install calibre ourselves though we will inform the users that we will install the software ourselves on their server as part of the installation procedure? (Just asking, since it would be better to use calibre at the start to avoid quality problems in the other conversion products that will result in bug reports)

Are you bundling or calibre into an installer that you give to your customers or are you providing a service where one of your people sits down with access to the customers sever, installs and setups up the everything they need?

Originally Posted by garylisbon

Just to be clear, calling ebook-convert from a java command (Runtime.exec) that executes command line arguments is not considered as linking right? (Not sure of the scope of the term linking in the license)

What you've described (using Runtime.exec) is not linking. Linking would be using a DLL from calibre.

[garylisbon]

Originally Posted by user_none

Are you bundling or calibre into an installer that you give to your customers or are you providing a service where one of your people sits down with access to the customers sever, installs and setups up the everything they need?

I guess it would be the 2nd scenario. In the terms/email of the users, they want us to do the installation and setup for them.

Thanks,
Gary