1) Pick a more sensible goal. $100 Grand to develop a multiplatform AutoHotkey is more than ambitious, it's unrealistic. It's hard to believe there would be enough interest to warrant that much financial support. For all I know it might take $100 grand to finish such a project in a few short years. But it's better to reach success in, say, 5 years than never reaching it at all. Even with plenty of internet adverts, a really snazzy video on YouTube, and the endorsement of some folks with influence, I doubt you could raise that much. It's better to aim a bit low and celebrate when you surpass your goal.
As an example, you mentioned the Kickstarter to create an open-source rewrite of LiveCode. That kind of educational project would appeal to universities, corporations, and others with deep pockets. My guess is that a multiplatform AutoHotkey would appeal to a different sort of crowd.
2) Consider alternatives to Kickstarter. While Kickstarter has many proponents and success stories, there are also many failures to reach a specified goal within a specified time limit. When that happens, the project ends and all the money is returned to donors. Just to start a Kickstarter project, you have to literally pitch a proposal to the Kickstarter group and hope they accept your submission. (Not all proposals are accepted.)
Kickstarter has name recognition and is the most popular, but it is over-hyped. There exists lesser known, but very similar alternatives. Might I suggest Indiegogo, "The world's funding platform" ? Unlike Kickstarter, even if you don't hit your goal an Indiegogo project will still give the option to keep the money and proceed with your stated objective. Though, if you do decide to keep it - despite not reaching your goal - Indiegogo will take a slightly larger share than if you had made your goal.
3) Such a project would need to be very clear about what the stated objectives are. Merely stating a desire to continue development of IronAHK is not specific enough. What kind of functionality can be promised for $100 grand? What about $50 grand?
4) Research is needed before a fundraiser is pitched. Perhaps it would be necessary to consider a few compromises to make IronAHK a success? As IsNull points out:
Besides lack of time, I think there is one thing which caused the IronAHK project to get frozen. AHK in its very nature is focusing on Windows, and not everything is easily ported nor do all Commands and Function really make sense on other OSs. Especially the different Desktop environments for the X Window System on Linux are pretty nasty to support. This affects the window manipulation and also the keyboard hooks. Some things are just not possible, or just with deep native inter ops.
Frankly, the project requires some very fundamental research for the very AHK core features...