Shareware is a type of proprietary software that is provided to users for free for a limited trial period. During the 1980s, Bob Wallace produced the first major shareware product called PC-Write. Shareware is typically lower cost than purchased software, ranging from $1 to $500 depending on the size and functionality, and provides users a way to try software before paying for it. The main differences between shareware and open source software are that shareware maintains the developer's proprietary rights and does not make its source code available while open source involves public availability of source code and a community of developers.