As to the widely adoption of Open Source Software (OSS) such as WordPress, Mozilla Firefox, Linux operation system, companies and organizations start to pay more attention and focus on developing FLOSS (Free/Libre/Open Source Software) projects. At the very beginning of the use of FLOSS development, genius developers used it for hacking purpose, but now people use it as a way to doing business or as a hobby to contribute own code to construct better software to the society. However, there are a lot of challenges in the communication between different roles in OSS communities, which we tried to find out from the research (Rantalainen, Hedberg, & Iivari, 2011). The source code in Open Source Software development is available in public and permits changes made by the public. Anyone with moderate computer skills is able to partake in a project. Generally, people work for free and contribute to OSS development as a hobby. (Hertel, Niedner & Herrmann 2003) An important factor influencing the OSS development is the ideology behind Open Source, which argues for freedom, sharing, openness of software, code quality and it enables contributors to achieve status and reputation. Nowadays, FLOSS is increasingly becoming used by everyday computing users in addition to the experienced technical users (Schwartz & Gunn 2009). This chapter introduces the various users that participate in OSS communities, how can they contribute themselves and what are their responsibilities. The traditional onion model has been explained, and also a new hypothesis model created by Hedberg and Iivari has been showed as a comparison to the traditional model, of which the former considers more about cooperating with HCI specialists during the development processes than the latter. User participation in OSS development plays an essential role and it has been a popular topic discussed in many research papers. Even though the research indicated that more than 90 percent of users are “passive user”, which means they do not use the system regularly and they 2/14 do not participate in system development, but they can still function as potential developers by reviewing, reporting and giving feedback to the system (Nichols & Twidale, 2006). However, it has been found both from Information System and HCI literatures, that users should take part in the development process and it is particularly important to motivate active user to take part in IT artifact development (Asaro, 2000; Iivari, 2008). Peters (2009) also agreed that users are important in OSS development because they test and evaluate the system by interacting with the system to accomplish their own task, also in a way that they spread their user experience to others and attract more users to be involved, which also motivated developers to improve the system into a more perfect way. Moreover, they support OSS development by participating and contribute financially to support for the development (Peters, 2009). Some other studies also support this viewpoint that users’ participation in OSS helps development substantially and more effectively (Zhao & Elbaum, 2003). 2.1.1 Core Members A survey study made by Ghosh and Prakash (2000) found out that, there is a large amount of cases in OSS project have very small core group. The core members normally take a large proportion of responsibilities and accomplish most of the works in a project. And the other participants in the large group, they basically play the role as a reminder (Ghosh & Prakash, 2000). Team leader and core developer can be classified as active developers in OSS community. They have the most influence and also carry out of core part of development process in a project (Ye & Kishida, 2003). Project leader as the person who started the project or mainly responsible to lead the project and show the directions (Ye & Kishida, 2003). Meanwhile, for core developers, who are master project programmers that responsible for coordinate with project leader and fully involved in the project and made significant contribution during the development. Project leader is not longer needed at that time because they share responsibilities and make decision within core member team by instead (Ye & Kishida, 2003). 2.1.2 Maintainers, patchers & bug reporters Besides to the core members, the other roles in OSS community also contribute themselves in different way. Readers, who basically only read the source code and try to understand it by not modifying, bug fixers and reporters contribute their effort by discovering, fixing and reporting bugs existed in the system. Moreover, contributors, which is one of main the development forces in OSS projects. They contribute themselves by developing new features and fixing bugs actively, regularly and continually (Ye & Kishida, 2003). 2.1.3 HCI specialists It has been argued that user involvement in information system research is important since it helps constructing better and useful IT artifacts from user point of view (Iivari, 2008). HCI specialists play essential intermediate role in dealing the communication issue between developers and users. They are crucially needed as a role to conduct surveys and interviews from user, so that to contribute the steer user research studies as the way to bridge the communication with developers (Ogawa, Ma, Bird, Devanbu, & Gourley, 2007; Paul, 2009). Some researchers state that HCI specialists are more acts like direct users in the involvement, since the communication to normal users always need intermediaries as the connections, and HCI specialists are the ones who can help the new entrant user, 2.1.4 The level of user roles In the onion model mentioned in Figure 1, there is no such place to show the position of your specialists. The traditional model of the AWS project has changed in one way or another in the current development model, since the current organization and the company pay more attention from the perspective of the end user to the show. Hedberg and Ivari (2009) proposed a new model to follow in the OSS community, which included all the important roles, HCI added. To understand the development process of open source software, one should focus on studying the structure of Open Source Software environment, the communities within it and and their participants’ roles. The community plays an important part in the likelihood of success in any Open Source Software project. 2.2.1 Problems in communication between the different roles Usability testing and reporting of bugs have both been suggested as ways to increase the rate of user involvement. (Zhao and Deek, 2005, 2006) However, non-technical users might be uninterested or even intimidated about using communication tools such as IRC, discussion forums, mailing lists, feature requests and bug reports (Ge, Dong & Huyang, 2006; Ye & Kishida, 2003; Cetin, Verzulli & Frings, 2007) 2.2.2 Suggestions User experience and usability issues differ from bugs and other issues, therefore they should be separated from one another. Both bugs and usability issues are generally collected into the same view with bug tracker and thus linked together. It would be advisable to have a dedicated tab, for example, for user experience issues in order to clarify the development process and reporting. (Bach et al., 2009). 3.1 Result of the research In this research paper, literature studies were conducted about the different user roles in OSS community, what are their responsibilities and positions, and how they should cooperate with each other so that to contribute themselves in a more user satisfaction way. The traditional onion model has been illustrated first, and consider the importance of HCI specialists role, another hypothesis model which is designed by Hedberg and Iivari has also been shown. All in all the study found out that it is important to allow users fully involved into OSS project, since their feedbacks and suggestions are crucial. 3.2 Limitations The limitations of this research study are related to relying on other researcher’s studies. Triangulation of the information, for example, poses a challenge when building a uniform view regarding the role of users in an open source software communities. There is no agreed terminology in this field, and hence analysing and combining the research findings of other researchers has been challenging. In addition, we have not conducted own survey research about the roles but merely are contributing to the field with our literature review contrasting the latest research findings. 3.3 Recommendation for future research Acceptance studies about the use of open source software may contribute to the general understanding of the open source software users. Understanding what affects the use of open source will help in building an understanding of the role of the user in more depth. Relevant research about OSS can be conducted by collecting research data in organizations and companies, and gain better understanding about different user roles among them. Specific comparative studies about the user participation in the different phases of open source software development would help in understanding how the role of the user is throughout an OSS project. There may be differences regarding the role and the rate of participation of user depending whether the project is in requirements phase, development phase, evaluation or testing phase. Such research would help in identifying different ways to motivate participation.