Thanks for taking interest in GroupDocs.Viewer.
First of all, it is important to tell you that GroupDocs.Viewer is a back-end, UI less API that allows you to render the document in the form that can be easily displayable in the front-end applications. Currently, the API provides Html based rendering and image-based rendering of the supported document formats. Furthermore, it also allows you to render the document as PDF document.
HTML based rendering: In HTML based rendering, the API generates the HTML representation of each page of the source document. You can easily manipulate the HTML content of each page and save it as an HTML file. For details, please visit Rendering Documents as HTML.
Image-based rendering: In image-based rendering, the API converts each page of the document into an image (PNG, JPG, BMP). You can easily save the image to your desired location and display it in your application to view the content of the document. For details, please visit Rendering Documents as Image.
As the API provides the back-end features of document rendering and it does not contain any built-in viewer control, therefore, you will have to create your own front end application to display the rendered Html pages or images.
We have also developed open source document viewer applications (listed below) using GroupDocs.Viewer for .NET that will help you understand the working of the API. You can also use these applications and modify them as per your requirements.
Yes, you can get the PDF as its original format using GroupDocs.Viewer (see this). However, you can not view/display the document in its original format directly in your front end application. The document is needed to be rendered in a format that is displayable in the front end application. For example, you can not view the Word document in your web application in its original format. However, you can do it by rendering the document pages as HTML pages or images.
The search feature is not the part of back-end GroupDocs.Viewer API. However, this feature is implementable in the front end application and currently it is available in GroupDocs.Viewer-for-.NET-WebForms-App for HTML based rendering.
In order to evaluate all the features of the API, please download the Examples project that contains the source code examples of all the features of the API. To learn more about the API, please visit the documentation.