以往之網際網路相關研究，並未就 Web 2.0一詞提出簡單明確且涵蓋廣泛之解釋，故本研究首先嘗試提出一 Web 2.0之通用意涵：「網路參與者更容易重組及排列網路元素的網際網路演化狀態。」，並將 Web 2.0從流行名詞轉而充分融入各網際網路服務的階段設定為後 Web 2.0時代。 近年來網際網路已經越來越朝向開放發展，而本研究發現開放的發展主要可分為三個階段：第一，於 Web 2.0時代以前，開放的機制即已奠定基礎，此階段主要的發展來自於技術與架構方面；第二，Web 2.0時代，開放的觀念與能力逐漸成熟，此階段的趨力主要來自於使用者與開發者社群之互動；第三，後 Web 2.0時代，企業之開放策略形成，正式進入商業與程序主導的開放階段。本研究並羅列混搭的類型，以之為涵蓋範圍，結合其成員及網路關係，試圖解構出網際網路的開放生態系。 在說明追求競爭優勢的傳統理論在 Web 2.0時代已經失效之後，本研究針對開放的動態策略互動進行脈絡化整理，建構出擴充超競爭理論的第五個競技場—開放競技場理論，其中，各動態策略互動之內涵與造成的影響分別為：使用者產生內容造成控制權移轉；開放內容混搭突破傳統網站壁壘；以開放 API 解放創新枷鎖；以開放平台收編第三方開發者；以開放社交資料收編中小型網站；以及資料可攜將所有高牆剷平。開放競技場的假想終點，就是一種所有服務、技術、內容，及資料等都完全開放的狀態。開放競技場的網際網路企業，一方面要追求開放以獲得競爭優勢，一方面又要避免達到沒有人有競爭優勢的完全開放狀態。 本研究並認為，台灣網際網路產業由於現存者的不作為，目前並未進入開放競技場，且因為缺乏開放競技場的動態策略互動經驗，廠商普遍而言難以進入超競爭之國際市場，僅能專注本地市場。 / Former Internet studies did not provide a simple and inclusive explanation to the concept of Web 2.0. Therefore, this study proposed a universal meaning of Web 2.0: "the Internet evolution stage in which its participants are more easy to reassemble and arrange Internet elements." Moreover, post Web 2.0 era is defined as the period when the buzzword of Web 2.0 becomes prevalent in Internet services. In recent years, the Internet is becoming more and more open. This study found that the development of openness can be divided into three stages. (1) Before Web 2.0, the open mechanism has already set its root. The development of this stage is a result of technology and architecture. (2) In Web 2.0 era, as the concept and capability of 'openness' are gradually mature, the driving force behind this stage involved the interaction of user and developer communities. (3) Following the formation of open strategy, the effects of business and process are predominant in post Web 2.0 era. The study has also listed the types of mashups, combining the players and their network relationships, to reconstruct the open ecosystem of the Internet. After showing that traditional theories in competitive strategy are invalid in Web 2.0 era, this study contextually discussed and organized the dynamic strategic interactions in open development, which expanded hypercompetition theory into its fifth arena, the open arena theory. The core ideas and consequences of the dynamic strategic interactions are as follows: (1) user generated content to shift the control; (2) content mashups to break the web strongholds; (3) open API to unleash the chains of innovation; (4) open platform to recruit third party developers; (5) open social data to absorb small and middle websites; (6) data portability to tear down all the walls. The end of open arena is supposed to be a status that all services, technologies, contents, and data are completely open to all. Businesses in open arena pursue openness to gain competitive advantages, while prevent total openness where no one has any competitive advantage. According to the study, since the inertia of the monopolistic incumbent, the Internet industry in Taiwan has not currently entered into the open arena. Lacking the experience of dynamic strategic interaction in open arena, it is generally difficult for businesses in Taiwan to tap into the global market, and thus limited to the local market.