A collection of $n \geq 1$ mobile robots/agents are located within a continuous domain $\mathcal{D}$. In the search problem the agents are tasked with finding a stationary target located at an unknown position within $\mathcal{D}$. In the rendezvous problem the agents are required to all converge to any single location within $\mathcal{D}$. In either problem the capabilities of the agents are described by a robot model $\mathcal{M}$ (describing, for example, speed constraints, the fault model, knowledge available to the agents, memory capacity), and the cost of a solution algorithm $S$ is described by a cost function $\mathcal{C}$ which assigns a real number $\mathcal{C}(S)$ to each $S$. The ultimate goal of either problem is for the agents to complete the desired task whilst minimizing $\mathcal{C}$ subject to $\mathcal{M}$. This thesis will be of the integrated form and will be composed of several published results concerning the problems of search and rendezvous by mobile agents in continuous domains.