ActiveState's David Ascher - Dynamic Languages-ready for the next challenges, by design:

"The driving forces for the creation of each major dynamic language centered on making tasks easier for people, with raw computer performance a secondary concern. As the language implementations have matured, they have enabled programmers to build very efficient software, but that was never their primary focus. Getting the job done fast is typically prioritized above getting the job done so that it runs faster. This approach makes sense when one considers that many programs are run only periodically, and take effectively no time to execute, but can take days, weeks, or months to write. When considering networked applications, where network latency or database accesses tend to be the bottlenecks, the folly of hyper-optimizing the execution time of the wrong parts of the program is even clearer. A notable consequence of this difference in priority is seen in the different types of competition among languages. While system languages compete like CPU manufacturers on performance measured by numeric benchmarks such as LINPACK, dynamic languages compete, less formally, on productivity arguments and, through an indirect measure of productivity, on how "fun" a language is. It is apparently widely believed that fun languages correspond to more productive programmers-a hypothesis that would be interesting to test."