Google is debuting on Tuesday a special category for education-related software in its Apps Marketplace, prompted by what it considers the success of its Apps for Education collaboration and communication suite.At launch, the education section of the Apps Marketplace will feature about 20 Web applications, including classroom managers, gradebooks and learning aides. Some of the applications are new to the marketplace, while others were there before.There are about 10 million end users of Google Apps for Education, which is free, and the new Apps Marketplace category is envisioned as a central repository where educational institutions can seek and evaluate applications for students, teachers and staff, said Scott McMullan, Google Apps partner lead, in a phone interview.Introduced in March of last year, the Apps Marketplace is an online store whose third-party applications are integrated in a variety of ways, like single sign-on and common UI navigation, with the Google Apps suite through a series of APIs. Google receives a commission from applications sold via the marketplace."With millions of users already using Google Apps for Education, LearnBoost saw an opportunity to be part of a bigger story in education. Google's involvement credibly signals that education is becoming more interesting to technology companies," said via e-mail Rafael Corrales , CEO of LearnBoost, which makes a gradebook application.BrainPOP, maker of learning aides and tools, was founded in 1999 and views Google Apps for Education and the marketplace as further proof that educational institutions are embracing the digital world in a major way."Every day we're seeing signs that this vision is becoming a reality. Great educational resources are already being discovered, shared, consumed, mixed, and evaluated online. The need for organizing access, permissions, storage, and formative assessment data is already here, and Google's early grassroots success among teachers bodes well for Google Apps," said BrainPOP COO Din Heiman via e-mail.