Batteryless, energy-harvesting systems could reshape the Internet of Things (IoT) into a more sustainable societal infrastructure. This article discusses the challenges and opportunities of batteryless computing, focusing on intermittent execution, energy management, and system design. Batteryless devices use capacitors instead of batteries to store energy, but energy is highly variable and unpredictable, leading to frequent failures. To address this, researchers have developed new programming languages, compilers, runtime systems, and architectural designs that enable real-world applications of batteryless devices. These systems must handle intermittent execution, ensuring memory consistency, timely output, and correct behavior despite frequent power failures. Batteryless devices face challenges such as restartability, memory consistency, and timeliness, which require careful design to ensure reliable operation. Researchers have also explored solutions for efficient and reliable batteryless communication, including techniques for energy-efficient data transmission and synchronization between devices. Additionally, the article discusses the need for formal foundations of intermittent computing to provide correctness guarantees, which are essential for applications such as medical devices and pervasive infrastructure monitoring. Security is another critical concern for batteryless systems, as they are vulnerable to attacks due to their embedded nature and limited resources. Researchers are exploring hardware-based solutions and secure protocols to address these challenges. The article also highlights the importance of energy-efficient computer architectures, such as reconfigurable dataflow architectures, which can significantly reduce energy consumption while maintaining performance. Finally, the article emphasizes the need for foundational infrastructure, including benchmarks, testbeds, and tools, to support the development and evaluation of batteryless systems. It also discusses the importance of user interaction with intermittently computing devices and the need for user-friendly interfaces and tools to make batteryless computing more accessible. Overall, the article outlines the key directions for future research in batteryless computing, emphasizing the need for interdisciplinary collaboration and innovation to achieve sustainable and efficient IoT systems.Batteryless, energy-harvesting systems could reshape the Internet of Things (IoT) into a more sustainable societal infrastructure. This article discusses the challenges and opportunities of batteryless computing, focusing on intermittent execution, energy management, and system design. Batteryless devices use capacitors instead of batteries to store energy, but energy is highly variable and unpredictable, leading to frequent failures. To address this, researchers have developed new programming languages, compilers, runtime systems, and architectural designs that enable real-world applications of batteryless devices. These systems must handle intermittent execution, ensuring memory consistency, timely output, and correct behavior despite frequent power failures. Batteryless devices face challenges such as restartability, memory consistency, and timeliness, which require careful design to ensure reliable operation. Researchers have also explored solutions for efficient and reliable batteryless communication, including techniques for energy-efficient data transmission and synchronization between devices. Additionally, the article discusses the need for formal foundations of intermittent computing to provide correctness guarantees, which are essential for applications such as medical devices and pervasive infrastructure monitoring. Security is another critical concern for batteryless systems, as they are vulnerable to attacks due to their embedded nature and limited resources. Researchers are exploring hardware-based solutions and secure protocols to address these challenges. The article also highlights the importance of energy-efficient computer architectures, such as reconfigurable dataflow architectures, which can significantly reduce energy consumption while maintaining performance. Finally, the article emphasizes the need for foundational infrastructure, including benchmarks, testbeds, and tools, to support the development and evaluation of batteryless systems. It also discusses the importance of user interaction with intermittently computing devices and the need for user-friendly interfaces and tools to make batteryless computing more accessible. Overall, the article outlines the key directions for future research in batteryless computing, emphasizing the need for interdisciplinary collaboration and innovation to achieve sustainable and efficient IoT systems.