Using someone else’s software in you app without obtaining their permission could constitute copyright infringement and end up in you getting sued. Whether your authorized use constitutes copyright infringemnet depends on how much you take and how you use it.

Wholesale Copying

Subject to some important limitations, copyright protects source code (code written in high-level computer languages consisting of English-like words and symbols readable by humans, such as C++, and Java), object code (the series of binary ones and zeros read by the computer itself to execute a program, but not readable by ordinary humans), microcode (instructions that tell a microprocessor chip how to work) and other forms of computer code such as Java byte code.

Copyright protects both applications programs (programs that perform a specific task for the user, such as word processing, will and trust writing, accessing the World Wide Web, bookkeeping or playing a video game) and operating systems and utility programs (programs that manage a computer’s internal functions and facilitate use of applications programs).

Wholesale copying or software piracy takes a variety of forms, including:

• Creating “new” software from old.
• Creating a “new” program by copying a substantial amount of the protected expression in a preexisting program, is a classic example of software piracy. end user piracy by companies and individuals. EXAMPLE: AcmeSoft, Inc., a large software developer, makes 100 unauthorized copies of a well known HTML editor program and distributes them to its employees.
• Counterfeiting published software. EXAMPLE: Fly By Night Software, Inc., a software distributor, makes 50,000 unauthorized copies of the popular computer arcade game, Kill or Die, and distributes them throughout the world.
• Online piracy. This includes uploading and downloading computer programs to and from the Internet and computer BBSs without the copyright owners’ permission.

Learn more about Copyright and Ownership Rights.

What About Copying Only a Small Amount of Code?

Copying only a small portion of a program’s code could constitute copyright infringement. Then again, it might not. Aparticular routine or subroutine or other piece of code may enjoy little or no copyright protection. In this event, copying it wouldn’t be an infringement. On the other hand, if the code is protected, copying only a small amount could be an infringement, particularly if it is a highly creative or important example of the programmer’s art. Copyright infringement has been found to exist where only 14 lines of source code out of a total of 186,000 lines were copied verbatim. (SAS Inst., Inc. v. S&H Computer Sys., Inc., 605 F.Supp. 816 (M.D.Tenn. 1985).) You’ll usually be better off not copying other people’s code.

Creating Unauthorized Derivative Works

Copyright infringement is not limited to the crude wholesale copying described above. It can take a more subtle form—creating “new” software from old, for example, by transferring a chunk of code to the new program and subsequently modifying it. If such a “new” program contains a substantial amount of copyrighted material from an existing program, it may constitute a derivative work. You need to obtain permission to create a derivative work from someone else’s software. Common examples of derivative works include:

• Updates and new versions. An updated or new version of an existing program, website, book, or other work is a most common example of a derivative work. Only the person who owns the derivative work’s rights in a work may create an updated or new version of it or permit others to do so.
• Translations. A translation of a work from one language to another—whether a human or computer language—is a very common type of derivative work. It is usually necessary, for example, to obtain permission from the copyright owner to translate a program into a new source code language.
• Transferring a work from one medium to another. Changing the medium in which an original work is fixed normally creates a derivative work consisting of the expression as fixed in the new medium. And, regardless of what new medium is used, a copyright infringement occurs if you don’t first obtain permission from the owner. For example, a person who uses a scanner to create a digital version of a copyrighted photograph is creating a derivative work.
• New works based on other underlying works. Any work based upon a preexisting work is a derivative work. Computer games are good examples. A computer game based on a movie, television show, board game, or other underlying work is a derivative work. Naturally, you need permission from the owner of the pre-exisiting work’s rights to create a new work based upon it.

Learn when Using Copyrighted Material is Acceptable.