Imposing some reasonable conditions on our spaces (I think semilocally-simply-connected ought to do), one works through **Exercise 1** $\mathbb{Z}[X]$, the free topological $\mathbb{Z}$-module continuously generated by a convenient space $X$ is an $E^\infty$ space; the maps $\mathbb{Z}[X] \to \mathbb{Z}[Y]$ induced by $ X \to Y \to \mathbb{Z}[Y]$ make this construction continuously functorial; these induced maps are again $E^\infty$ maps. **Exercise 2** a weak homotopy equivalence of spaces $X \simeq X'$ induces a weak homotopy equivalence of $\mathbb{Z}$-modules. **Exercise 3** For a cofibration $X \to Y$, there is a pullback square $$ \begin{array}{c} \mathbb{Z}[X] & \to & \mathbb{Z}[Y] \\ \downarrow & & \downarrow \\ \mathbb{Z} & \to & \mathbb{Z}[Y/X] \end{array}$$ **Exercise 4** $\pi_0 \mathbb{Z}[*] \simeq \mathbb{Z}$; otherwise $\pi_k \mathbb{Z}[*] \simeq 0$. **Exercise 5** the functor $X\mapsto \mathbb{Z}[X]$ preserves colimits of sequences of cofibrations. **Corollary** We have verified that the functors $\pi_k \mathbb{Z}[X]$ satisfy the Eilenberg-Steenrod axioms for ordinary homology. ***** Again using the natural map $\mathbb{Z}[X] \to \mathbb{Z}$; write $\tilde{\mathbb{Z}}[X]$ for its kernel. To complete the exercises, მამუკა ჯიბლაძე's cogent remark explains why the natural map $SP^\infty X \to \tilde{\mathbb{Z}}[X]$ is an equivalence for connected $X$s. But yes, it really is magical!