I created Chemonstrating to solve a problem I saw in the chemical demonstration space- but not every wheel needs reinventing, and lots of fantastic chemistry and chemistry education resources already exist. But not everyone knows about all of them! I have done my best to collate resources others have created that I find to be clever and/or useful. I don't claim resonsibility for any of these resources- I am linking here to external websites I have no control over.
I am working on an embeddable periodic table for Chemonstrating... that said, Michael Dayah's PTable website is one of the best online periodic table resources I have encountered. It can display all sorts of different elemental properties and periodic trends, and the design is clean and easy to use.
BioIcons provides a free, MIT-licensed alternative to paid sources of premade SVG icons for constructing scientific figures- some of which are used on this very website! While BioIcons is geared primarily towards biology research, I have found it to have most of what I need for chemistry demonstration figures, and it is every expanding.
I'll let DataThief speak for itself: "DataThief III is a program to extract (reverse engineer) data points from a graph. Typically, you scan a graph from a publication, load it into DataThief, and save the resulting coordinates, so you can use them in calculations or graphs that include your own data."
Not Voodoo is a project run by Alison Frontier at the University of Rochester aimed at providing resources for synthetic organic chemists. It is packed chock-full of much of the same kind of content I strive to create here, but has the distinct advantage of having been around since 2004 and being run by people much more experienced than I!
Precisely what it says on the tin: "The NIOSH Pocket Guide to Chemical Hazards (NPG) informs workers, employers, and occupational health professionals about workplace chemicals and their hazards. The NPG gives general industrial hygiene information for hundreds of chemicals/classes. The NPG clearly presents key data for chemicals or substance groupings (such as cyanides, fluorides, manganese compounds) that are found in workplaces. The guide offers key facts, but does not give all relevant data. The NPG helps users recognize and control workplace chemical hazards." Also, it's searchable!