Softwares now-a-days have become the life line of modern day organizations. Organizations cannot think of doing their tasks effectively and efficiently without softwares. The extremely competitive environment, zero deficiency and enhanced productivity has made it mandatory for the organizations to carefully choose the appropriate software after comprehensive needs assessment. Softwares simply their tasks and saves a lot of precious time which can be utilized in managing other important issues. Libraries also need softwares if they want to create a parallel digital library with features which we may not find in a traditional library. There are several open source softwares available to create a digital library. For this, firstly the library professionals should be aware of the advantages of open source software and should involve in their development. They should have basic knowledge about the selection, installation and maintenance. Open source software requires a greater degree of computing responsibility than commercial software. Digitization involves huge money to create and maintain and the OSS appears to be a means to reduce it. Among these, DSpace and Greenstone are becoming more popular in India and abroad. This paper deals with the comparison of these two popular OSS from various points of view. The comparative table may help the professionals who are planning to create a digital library.