This may sound like a desperate echo of 1998, when Netscape, struggling in Microsoft's choke holding, published the source-code of its web browser (an initiative that yielded few real results until this June, when the first serious new version of the open-source browser, Mozilla, was released). Yet RealNetworks is not playing defense. It is trying to encourage the creation of a common multimedia software structure for every kind of file format and device, thus defeating Microsoft's ambitions in this promising market.
The firm hopes that others in the industry (volunteer programmers, media firms and hardware makers) will take the code, called Helix DNA, improve it and make it run on new devices, such as mobile phones and home stereos, turning RealNetworks' software into an industry standard. Clever licensing terms are supposed to ensure that this standard does not split and that the firm still makes money.
Individual developers, universities and other non-profit organizations can modify the software as they please, and even redistribute it for free, so long as they also publish the source-code for their changes. This is a sort of payment in kind, for RealNetworks is then allowed to use these contributions. Finns, on the other hand, must pay royalty fees if they distribute mom than lm copies of the code. They also have to make sure that their software works with other Helix DNA products. The software's development community already has 2,000 members. And several hardware makers back the effort. But there are risks. Afraid of piracy(盗版), media groups are suspicious of anything that might be related to hackers (although they also do not want to depend on, and pay for, technology controlled by Microsoft). The self-created competition could also hurt RealNetworks if customers decide its commercial products, which will be based on the open source-code but with extra features, are not worth paying extra for.
RealNetworks' move is another sign that the software industry is going hybrid. Mixing elements of proprietary software, where the source-code is tightly controlled, with open-source programs enables firms to expand a market, harvest the ideas of others and, they hope, still make money. Even Microsoft is edging this way: it recently announced that partners can now look at-- but not modify or re-use-- the source-code for Passport, its controversial digital-identity service.
By what way does RealNetworks attempt to prevent Microsoft's ambitions?
A.Publishing the source code.
B.Using RealNetworks' achievements.
C.Protecting intellectual property.
D.Accusing of Microsoft.
第1题
静态时,正常成人每分钟通过肾脏的血循环量哪项最正确 ()
A.500ml
B.1000ml
C.1500ml
D.2000ml
E.3000ml
第3题
关于心脏每分钟输出量的表述,哪项正确
A、安静仰卧时,成人每分钟输出量是10L
B、健康人运动时,每分钟输出量可达25L
C、运动时,健康人的心输出量增加与代谢量或通气量的增加完全一致
D、心输出量=每分钟摄氧量/动静脉氧分压差
E、良好训练者安静时心率较慢,故心脏每分钟输出量减少
第4题
肾小球滤过率是指()。
A.每侧肾脏每分钟生成的滤液量
B.两侧肾脏每分钟生成的滤液量
C.每分钟一侧肾脏生成的滤液量
D.每分钟两侧肾脏的血浆流量
第5题
肾小球滤过率是指
A.两侧肾脏每分钟生成的超滤液量
B.一侧肾脏每分钟生成的超滤液量
C.两侧肾脏每分钟生成的尿液量
D.一侧肾脏每分钟生成的尿液量
第7题
肾小球滤过率是指
A.两侧肾脏每分钟生成的超滤液量
B.一侧肾脏每分钟生成的超滤液量
C.两侧肾脏每分钟生成的尿液量
D.一侧肾脏每分钟生成的尿液量
第8题
肾小球滤过率是指
A.两侧肾脏每分钟生成的超滤液量
B.一侧肾脏每分钟生成的超滤液量
C.两侧肾脏每分钟生成的尿液量
D.一侧肾脏每分钟生成的尿液量
第9题
肾小球滤过率指
A.每侧肾脏每分钟生成的原尿量
B.每分钟两肾生成的超滤液量
C.每分钟两肾生成的尿的总量
D.每分钟每侧肾脏通过的血浆量
E.每分钟每侧肾脏的血浆滤过量
第10题
下列除哪项外,其余均符合对肾的描述:
A、肾脏可随呼吸移动
B、正常成人肾脏厚度为4.0~5.0cm
C、肾脏位于腹膜内
D、成人肾脏长度为10.0~12.0cm
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