Licensing 101 for using free tools to develop a program to sell

Question

I have read so much on licensing, but still don't understand what I can use for my situation.

I want to develop a program (with a sql db) and after working out some the bugs (with the help of testers), maybe sell some copies. (Please don't advise me on whether this is a good idea, my question is about licensing.)

I want to use free tools to create it with, but be able to legally sell it later. SaaS isn't an option. Can someone point me to a plain-English primer on licensing for my situation, or tell me what my options are? As I said, I need a sql db (haven't decided between serverless or server ability) and the rest.

(I have some beginner's programming experience, but I will have to learn by doing in whatever language I choose, so I'm pretty open.)

Thanks.

Answer 1

Have a look at the FSF website. The free software foundation has quite a lot written on the pros and cons of the various open source license environment.

Answer 2

Most likely, you'll be able to pick any license you want. Very few (if any) tools dictate the licensing of the output you create with them. For instance, GCC is released under the GPL, but you can compile closed-source binaries with it, no problem.

As for SQL, that should be easy. Most SQL databases (MySQL, Postgres, etc.) operate via a client-server architecture, so you're not embedding or linking to the database code in your program, and thus you don't have to use a license compatible with those database systems. You do link to SQLite code when using SQLite, but SQLite has such a permissive license that you can use it freely in pretty much every project (even closed-source projects), regardless of their licensing.

Answer 3

You can sell your software in whichever license you want to.

And developing a program in a language and compiling it to machine code is not derived work and may be distributed without being influenced by the compilers license.

Meaning: If you compile something with GCC (GPL) you are free to sell it. If you buy MS Visual Studio (or use the free express version): same thing.

Another question is whether the used runtime library is free. We are lucky on that regard: Both the glibc or msvcrt are liberally licensed or already distributed with windows.

If you want to use additional libraries, you will have to look at their respective licenses:

• If it's GPL, you will have to license your own work under GPL, too.
• If it's LGPL or BSD style, you are better of: You still have to respect the license of the lib, but you can sell your program as closed source.

As you mentioned you want to use SQL. There are several common options:

• MySQL - Special case: It's dual licensed! In most cases: If you want to sell a program including MySQL, you'll have to buy a commercial license.
• MSSQL, Access: You'll have to pay MS.
• PostgreSQL: BSD style license!
• SQLite: Public domain. Do what you like.

Answer 4

First, worry about making something worth selling. You aren't likely to produce anything of salable quality without some experience with your tools.

Second, you haven't told us about anything like choice of platforms. I'd be happy to give you advice on how to build something on Linux, for example, but you may not be interested.

Third, for most mainstream languages, there are tools available at no cost that will do what you want. Narrow things down according to your need, and if necessary then you can ask about licensing.

For specifics:

The compiler you use almost certainly doesn't matter. With very few exceptions, nothing you write with any compiler will have license restrictions.

Check any libraries. Avoid ones usable only under the GPL, since they won't suit your business model. Most other Free/Open Source licenses will work for you. Exercise the same care if you copy source code from anywhere.

The database license may or may not matter, depending on how your program communicates with it. If it's linked in, avoid any with the GPL. If it will run as a separate process, make sure it's one you can redistribute, because the GPL won't apply.

Answer 5

Final note on GPL.

You just have to offer your source code if your work is a modified version of a GPL software. For instance you take a GPL driver, add a couple - or a bunch - of code and you want to sell it. You can do it, you just have to offer your source code.

Other example. You take Linux, you add some fancy stuff and you try to sell it as: ChrisLux you can do it also, but since you're modifying a GPL software you have to publish your source code.

On the other hand, if you just use a GPL software unmodified just to run your own program, you may keep your source code closed ( and sell it also ).

For instance, you create a new program to ... whatever, and then you charge for it, and it runs on Linux. You didn't modify Linux, so you shouldn't offer your source code. Same goes for libraries, if you have to ship them with your product, you just have to include its license in your program, something like: "ChrisCthopia uses this and this and this library".

Here's an interesting article that may help you: General Public License, explained