由於資訊科技與生物科技相關研究的進步，樹編輯距離的重要性也愈趨明顯。像是XML文件比對、RNA二級結構的研究、編譯器的最佳化、影像分析、自然語言處理等許多領域，只要是能夠轉換成樹對樹比對的問題皆可使用樹編輯距離的方法做分析比較。計算樹編輯距離的演算法非常多，例如像1979年Kuo-Chung Tai[6]正式提出樹編輯距離的問題，當時將樹編輯距離稱做Tree-to-Tree Correction Problem。後來Kaizhong Zhang and Dennis Shasha[5]在1989年提供一個比較好的演算法，且此演算法成為經典之一。Philip N. Klein[8]也在1998年提出的演算法改善了Zhang與Shasha演算法[5]的最糟情況下的時間複雜度。

然而卻找不到針對樹編輯距離提供視覺化過程的軟體工具，因此有必要提供一個工具解決這個問題。本論文介紹一套軟體工具，此工具可以讓使用者使用某些方式建立樹並執行樹編輯距離的演算法。建立樹的方法有兩種，第一種方法是填入一些適當的參數隨機產生相對應的樹；第二種方法是假設使用者想建立某一特定結構的樹，只需要在工具上填入某相對應的序列即可產生該樹狀結構。利用此兩種方法建立好所想要的樹狀結構之後，在節點上使用滑鼠連點兩下會出現設定節點標籤的視窗。一切設定好以後，最後將根據其演算法執行的結果將其過程以視覺化的方式呈現。

本篇論文介紹的工具使得未來樹編輯距離相關領域的研究變得更方便，藉由將結果視覺化的功能，減去以往人工比對的困難及時間，相信對於未來的研究會有相當程度的幫助。

Study of tree edit distance problems is more and more important because of the advancement of the related study of information technology and biology. There are a lot of algorithms for tree edit distance problems. For example in 1979, first to give a formal definition to tree edit distance is Kuo-Chung Tai[6]. Then Kaizhong Zhang and Dennis Shasha[5] provide a better algorithm in 1989, and their paper becomes one of the classic papers in the field of tree edit distance problems. Philip N. Klein[8] also provides another algorithm to solve tree edit distance problems in 1998, and it improves worst case of time complexity of the algorithm[5] Zhang and Shasha provide.

However, there is no related tool to visualize the result of tree edit distance problems, so it is necessary to provide a tool to visualize it. This thesis introduces a software tool. This tool can let user create trees by some methods and then do the algorithm of tree edit distance problems, and finally it provides a visualizing processes according to the result of some specific algorithm.

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