In modern software development, software localization is a key process to support distribution of software products to the global market. During software localization, developers typically convert all user-visible strings, resource files, and other culture-related elements to the local versions that are well accepted by local users. Despite the popularity of software localization, there have been few studies on the its current status in software practice, such as the proportion of localized projects, the most popular locales, and more importantly, the quality of software localization. In this paper, we present an empirical study on the status of software localization in open source projects. We find from that, popularity of software localization varies a lot in different User Interface (UI) frameworks and domains. Furthermore, we surprisingly find that only about 60% of string keys are actually translated on average in localized top software projects and software localization often span a long period of time in the software development history.