The high cost of creating and maintaining software and hardware infrastructures for delivering services to businesses has led to a notable trend toward the use of third-party service providers, which rent out network presence, computation power, and data storage space to clients with infrastructural needs. These third party service providers can act as data stores as well as entire software suites for improved availability and system scalability, reducing small and medium businesses' burden of managing complex infrastructures. This is called information/application outsourcing or software as a service (SaaS). Emergence of enabling technologies, such as service oriented architectures (SOA), virtual machines, and cloud computing, contribute to this trend. Scientific Grid computing, on-line software services, and business service networks are typical examples leveraging database and software as service paradigm. In this paper, we survey the technologies used to enable SaaS paradigm as well as the current offerings on the market. We also outline research directions in the field.