First, congratulations to Pleco for all the success and the expected revenue windfall!
I am very pleased that Pleco has released an integrated e-book version of Wilkinson's
Chinese History! I think that Pleco is best served by expanding to meet the needs of sinologists and other heavy academic users, so a project that would serve this group seems ideal.
Most of Pleco's expansion I see as improving the already good Pleco Chinese-English dictionary, but if I was pressed for an idea it might involve some kind of grammar resource for classical Chinese. I often use an application on my phone called
Kanji-kai, which is an ios version of a relatively new Literary Chinese-Japanese dictionary. One of the features of this includes explanations for how to these characters can be translated into classical Japanese depending on the way the character acts grammatically in a given text. This is the traditional Japanese way of deciphering a Chinese sentence called
kanbun kundoku (literary Chinese explanation reading). This is just such an excellent resource for reading a word correctly, and nothing comparable exists in English. The grammar examples in
A Student's Dictionary of Classical and Medieval Chinese are not nearly as comprehensive. In English, the best we have is Pullyblank's
Classical Chinese Grammar. In fact, many of Kroll's examples seem to have been taken from Pullyblank -- and this resource is just not very practical for deciphering texts on one's own. Such a project seems though beyond the scope of what Pleco could possibly do at the moment, but perhaps something could be done.
Maybe what would be most useful would be a database of translated Chinese texts with the matching corresponding English, which could be viewed side by side and searched through. Of course, only very authoritative and good translations should be included in such a database. The website Chinese Text Project has already done this to a certain extent, and it includes the 19th-century sinologist James Legge's excellent translations of the Chinese classics. These texts are may be no longer under copyright restrictions, so would this be a possible start for such a project.
I have attached the index to Morohashi with the permission of its author Nomura Hideto. I have rearranged the data so that it can be uploaded as a Pleco user dictionary. For the Pleco Sinologists who read Japanese, it is extremely useful. Yet, there are some characters which appear as a black box (■) now and I it seems unproductive in the scheme of things to spend time fixing it. Nevertheless, before uploading this user dictionary I felt the lack of Morohashi was Pleco's only flaw after it got Hanyu Da Cidian.
In some ways Hanyu Dacidian is almost all one needs. After that--it just takes practice, a lifetime of practice. Pleco should make sure to get the updated versions of this dictionary as soon as it comes out. This step was really the most important for Pleco, and it is difficult to imagine how to improve upon this. Of course, this attached Morohashi index- from my experience it is a better dictionary at defining words, in part because it is in Japanese and not Chinese so it allows for a certain distance. Hanyu Dacidian is best for better providing the first use of a word, as the first example given is usually from the time period when the word first appeared with a particular usage.
Personally, the top of my wishlist is either a database of translated Qing documents to English or a good dictionary of the literary Chinese which appears in official documents of imperial China. I'm thinking mostly 17th, 18th, and 19th-century official documents. I am aware that members of the Harvard class "Qing Documents" have over the years compiled a very limited Chinese-English lexicon of this vocabulary, but I wish for something much more comprehensive. Perhaps if a Chinese-English dictionary of such a genre were to be compiled it would combine the above source with an English translational of the lexical data from the relatively short 200-something page Japanese
Chūgoku rekishi kōbunsho dokkai jiten 中国歴史公文書読解辞典 (A Dictionary for Understanding Chinese Historical Offical Documents). Even this Japanese dictionary though is too limited, and in fact, one of the best sources along with Morohashi, Hanyu Dacidian, ABC, and Grand Ricci for reading these official documents that I know of is the Aichi University Chinese-Japanese Dictionary 愛知大学中日大辞典. There is a dictionary file for the application Lingoes of this last dictionary, but I would rather use this dictionary in Pleco so that I can save time by not looking up the same word again. Is there any way to make a converter of .ld2 files into a file that would work in Pleco? There are many dictionaries that I would like to import here.