I find the OP to be off-base in critique of the LightTable concept. To be sure, the concept has some likely drawbacks and would need real-world application to g

I find the OP to be off-base in critique of the LightTable concept. To be sure, the concept has some likely drawbacks and would need real-world application to gauge viability, but I thought the critique by comparison to Eclipse missed the point. If there is anything that good design has taught us, it's that doing things better has significantly greater value than simply doing more things. For example, the first comparative in this critique is the "docs everywhere" feature. The OP shows that the LightTable concept "eats up half the screen", "can't resize", etc. while showing that Eclipse has the same feature (with the javadoc tab at the bottom of the screen.) The OP sees documentation show up in both places, so it's called a wash/irrelevant. When I view those same two screenshots, I see a significant difference. In Eclipse, I see yet another tab/doc/thingy with information crammed in it; in LightTable, I see information displayed in parallel with the code, not having to compete for screen space. The OP's comment about documentation "eating up half the screen size" implies that more information on the screen is better than less information. I find the LightTable design in this scenario as saying some information is more important than others. It's mostly just aesthetics, but aesthetics is kind of the point behind LightTable.