# Review of Web Mapping: Eras, Trends and Directions
## 1 Introduction  
The United States Vice-President [PERSON]'s 1998 speech on digital earth technologies created an increased awareness of the value of geospatial information and its necessity to be available online and accessible to many users globally. [PERSON]'s vision was to harness technology and people to generate an immersive visual experience of travelling through virtual geographic space and time to understand our earth [1]. He identified the focus on applications such as conducting virtual diplomacy, fighting crime, preserving biodiversity, predicting climate change and increasing agricultural productivity. Interestingly, the two decades following that have seen huge developments of technologies and collaborative environments that bring people and information together, including digital globes, high speed communication networks, mobile wireless environments, location-based services, cloud computing and Web GIS. However, we still encounter many challenges and barriers including linking information around geographic location, analyzing and handling big geospatial data, discovering and interpreting intelligent information, immersive understanding of our digital Earth, harnessing crowdsourcing opportunities and communicating information to the global public in a manner that is contextualized and understood [2; 3].  
Since the beginning of the web and the first World Wide Web conference in 1994, the interactions among and between information and people have evolved dramatically. The web now is not simply a developing technology for content, but involves people who generate content, communicate andinteract in collaborative environments [4]. New user needs evolve which are accommodated in further technology developments, which in turn lead to wider usage and additional user needs creating an iterative cycle of technology development and user/application growth and expansion.  
Moreover, from the technological point of view the methods and tools for making maps available on the web have changed dramatically. The early origins of web mapping applications were \"simply\" tools allowing agencies and individuals to publish maps with user choices limited to browsing, zooming, panning, and turning on/off layers. The users were supposed to be active readers of the data but passive with respect to the possibilities of uploading pieces of information to the map itself and performing often-needed spatial analyses. Today, web mapping applications are introducing a broader range of functionality, including what traditional desktop GIS has provided but expanding beyond that to incorporate growing application requirements, with the advantage of being able to share content and analyze map data on the web.  
In this paper, we want to outline the evolution of web mapping taking into account the perspectives of the designers/developers (experts/scientists) and of the users (novice and occasional users). The remainder of this paper is organized as follows. In Section 2, we provide a brief discussion about web mapping in general, i.e., its definition, main characteristics, and how to identify the web mapping eras. In the two sections that come after, we then discuss the trend of the web mapping, considering the following eras: static, dynamic, services, interactive, collaborative, digital globe, mobile, cloud and intelligent (Section 3) and the directions in the web mapping eras (Section 4). In Section 5, we summarize the paper with some concluding remarks.