Collections of images and quantitative, numerical information about morphological dynamics support understanding the molecular mechanisms of development. Recently we conducted RNAi experiments targeting all 351 essential embryonic genes reported in the previous genome-wide RNAi screening for C. elegans. We recorded three-dimensional time-lapse, i.e., 4D differential interference contrast (DIC) microscopy images of developing embryos at 66 consecutive focal planes spaced at 0.5 um for 2 hours at 20 seconds intervals. We obtained a collection that includes 33 sets of quantitative data, such as 3D coordinate values of nuclear regions and their dynamics from 1 to 8-cell stage, for wild-type embryos and 1,142 sets of quantitative data for RNAi embryos corresponding to 263 essential embryonic genes. We detected over 26,000 phenotypic alterations for 421 phenotypic characters, such as cell division timing and division axis orientation from the collection (Kyoda et al., bioRxiv 2020). To make the collection openly available, we have developed Worm Developmental Dynamics Database 2 (WDDD2; https://wddd.riken.jp/), as the successor of Worm Developmental Dynamics Database (WDDD;
http://so.qbic.riken.jp/wddd/), with a completely new implementation using modern web frameworks such as Django and Three.js. WDDD consists of images and quantitative data of 50 sets of wild-type embryos and 136 sets of RNAi embryos corresponding to 72 of the 97 essential embryonic genes on chromosome III, with sparser time intervals, but WDDD2 needs to handle ten times more or over. The database shows nuclear division dynamics information interactively as a combination of 4D DIC images and 4D visualization of quantitative data. The system displays the region of the nuclei and the center of gravity of them as wireframes in 3D space, and the user can select to view the data at a specific time or all time points simultaneously. The related cell images are displayed next to the wireframe. The image and wireframe's viewpoint can be manipulated synchronized but freely by pointing device movements to compare them to each other. The 4D DIC images in the original microscopy manufacturer's format are openly available by download from the database. The quantitative data are also openly downloadable in the unified format for biological dynamics, BDML/BD5 (Kyoda et al., 2015; 2020). We plan to develop Web APIs in the future to use images, quantitative data, and phenotypic characters for analysis without download.