## 2 Definitions and Methodology  
The concept of Web 3.0 started emerging much earlier than the coining of the term \"Metaverse\" in 2021 by Meta, the parent company of Facebook. Web 3.0, known initially as the Sematic Web, was an initiative to make Web 2.0 machine-interpretable through heavy use of metadata and actually emerged sometime in the early 2000s. Various authors, namely [PERSON] et al. and [PERSON] in their papers [4; 5], peg the \"birth\" of Web 3.0 at the beginning of the 21 st century. The term was popularized in an article written by [PERSON] in The New York Times in 2006 which explored Web 3.0's viability as a business model [6]. In the context of the metaverse, Web 3.0 acts as the \"vehicle\" which enables users to enter the virtual worlds of the metaverse. Concepts that have now been associated with Web 3.0, such as blockchain, AI, augmented reality (AR), virtual reality (VR), and decentralization are also considered intrinsically linked to the metaverse. Blockchain is a well-known concept that has witnessed a rise in notoriety due to its pivotal role in enabling cryptocurrency and NFT transactions. In the metaverse, cryptocurrencies are to be used as the de facto currency for any sort of transactions, therefore making blockchain a cornerstone of metaverse development. The concept of using cryptocurrencies is linked to another key factor of Web 3.0, decentralization. In the metaverse this leads to the elimination of middlemen like banks or financial institutions, and the decentralization of monetary policy. However, it is important to note that blockchain also has other uses in the metaverse such as recording options in virtual elections or preserving the privacy of data. The role of AI and Machine Learning is not as clear in the metaverse as that of blockchain. Since the metaverse is in the very early stages of development, and is currently void, the role of AI is not very clear. In Web 3.0, AI and ML are linked to the semantic web. Artificial intelligence develops a better understanding of the context in which Web 3.0 functions by using the semantic web's metadata. This is true of an AI's basic functioning principles in the metaverse as well, but what exactly the purpose of AI will be for the end user is unclear. However, that does not stop one from speculating on a number of AI applications in the metaverse: to help users with searches, act as guides, automate day-to-day tasks, and more. From a software development and computer programming perspective, all of Web 3.0's facets can provide several challenges of varying degrees of difficulty. A simple use case, such as securing a cryptocurrency wallet, can quickly become complex when factoring in Web 3.0's, and the metaverse's, decentralized nature. Wallets would be available on multiple devices, with different operating systems, could be accessed by different applications, both for viewing purposes and for purchasing, and would need tracking through blockchain-ledgers, involving smart contracts to some degree. A software developer would need to take into account all of these factors, as well as concerns related to architecture, design and clean code when implementing a Web 3.0 application. Java is one of the most popular programming languages in use today, and it behooves us to take a closer look at specifically which tools and libraries from the vast Java ecosystem are most popular, and useful, in developing Web 3.0 applications inside the metaverse. The robustness of Java as a software development ecosystem, not just as a programming language, makes it an interesting candidate for an in-depth Web 3.0 tooling review. The Java Virtual Machine (JVM) is one of the most performance-driven runtime environments currently available and has expanded its list of supported languages greatly. While Java is still, by and large, the most popular programming language that uses the JVM, others have emerged recently. The most notable of these is Kotlin.