My non-Mandarin colleagues have been using
英文也好，中文也好
lately and I assumed from their context they meant both languages are equal in whatever comparison they were making.
When I looked it up I found it to mean "might as well, whether...or..."
How can I use 也好？ Is there more (or less) colloquial equivalents? How is 也罢 different?
Both A也好, B也好 and A也罢, B也罢 construction mean "whether A or B". It is usually spoken to show indifference when faced with two options or when the choice really doesn't matter. The explanation from 汉典 says the following:
A也好, B也好
表示不论这样还是那样都不是条件
Example: 插秧也好，收割也好，都不要误了农时。
A也罢, B也罢
表示不以所列举的情况为条件
Example: 运砖也罢，整地也罢，保证超额完成任务。
When used together, people would normally associate 也好 to a positive choice or action and 也罢 to a negative one. For example:
你去也好，不去也罢，都与我无关。
Note that for this A也好, B也罢 construction, the sequence is always 也好 first followed by 也罢.
Yes, when using 也好 as "A也好, B也好", it's different than use it alone. I partially confirm the answer provided by Question Overflow, but I don't think there is a different about positive/negative.
If using 也好 alone, like:
A: 我们去公园吧？(Shall we go to the park?) B: 我们还是去购物吧。(I'd like us to go shopping.) A: 也好。(All right.)
this mean the proposal from another is not same as yours but still acceptable.
