This week, three Software stocks are improving their overall rating on Portfolio Grader. Each of these rates an “A” (“strong buy”) or “B” overall (“buy”).

This week, Vringo Inc. (AMEX:VRNG) is making solid headway. The company’s rating improves to an A (“strong buy”) from last week’s B (“buy”) rating. Vringo provides products for mobile video entertainment and personalization. Shares of the company have increased 34.9% over the past month. For more information, get Portfolio Grader’s complete analysis of VRNG stock.

JDA Software (NASDAQ:JDAS) is bettering its rating of C (“hold”) from last week to a B (“buy”) this week. JDA Software Group provides software solutions that address the supply chain management, business process, analytic application, and e-commerce requirements of the retail industry. Shares of JDAS have increased 33.8% over the past month, better than the 5.6% decrease the Nasdaq has seen over the same period of time. For more information, get Portfolio Grader’s complete analysis of JDAS stock.

Rosetta Stone (NYSE:RST) boosts its rating from a C to a B this week. Rosetta Stone develops, markets, and sells language learning solutions consisting of software, online services and audio practice tools primarily under our Rosetta Stone brand. For more information, get Portfolio Grader’s complete analysis of RST stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.