One manner of protecting computer software in Canada is by
owning copyright in the underlying code. Under Canadian law,
copyright subsists in both the source code and assembly code of
computer software. However, it is a well-accepted principle of
copyright law that copyright only protects expressions of ideas,
and not the underlying ideas themselves. For works like software,
which often implement ideas, how far does copyright protection
extend? Put another way, how different must software be to avoid
infringing copyright in other software? Does the requisite
difference depend on factors such as whether or not the software
implements commonly used algorithms, libraries, or interfaces such
as APIs? Unfortunately, there is no clear answer. However, two
cases provide some guidance on this issue.
