Simplicity is the property, condition, or quality of being simple or un-combined. It often denotes beauty, purity or clarity. Simple things are usually easier to explain and understand than complicated ones. Simplicity can mean freedom from hardship, effort or confusion. It may also refer to a simple living lifestyle.
Openness is a philosophy that is being used as the basis of how various groups and organizations operate. It is a relatively new term to describe this general way of doing things.
It is typified by communal management, and open access to the information or material resources needed for projects; openness to contributions from a diverse range of users/producers/contributors, flat hierarchies, and a fluid organisational structure. (source: wikipedia)