As expected, Norway-based Web browser developer Opera made its debut on the Oslo Stock Exchange on Thursday, with shares rising slightly in morning trading. “The browser maker said its issue of 12.5 million new shares was oversubscribed by 20 times, with 83 percent of subscribers being foreign institutional investors,” reports CNET News.com. “Shares rose from 10 kroner ($1.42) to about 10.3 kroner ($1.46) by mid-morning. While positive, it’s a far cry from the explosive initial public offerings of the late 1990s.”